The Land Administration Domain Model 'Survey Package' and Model Driven Architecture Presentation of

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The Land Administration Domain Model'Survey
Package' and Model Driven Architecture
Presentation of Master of Science Thesis

• Jan van Bennekom-Minnema
• mail_at_janvanbennekom.nl
• MSc Programme GIMA
• http//www.msc-gima.nl

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Agenda

• Introduction
• Highlight main topics and MSc thesis project
• Details on Research Topics
• Land Administration Domain Model, Model Driven
  Architecture, constraints in UML models, Kadaster
  survey measurements
• Model Driven Architecture Prototype
• Transformations from PIM to PSM
• Analysis of quality/accuracy of Dutch cadastral
  map
• Conclusion
• Revisit research question, conclusions,
  recommendations

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INTRODUCTION

• Land Administration Domain Model 'Survey Package'
• Object Constraint Language
• Model Driven Architecture
• Kadaster Project "Registration Map Quality"
• MSc Thesis Project
• Objective
• Research Question
• Approach

Abbreviations LADM Land Administration Domain
Model LADM SP LADM's Survey Package MDA Model
Driven Architecture PIM Platform Independent
Model (e.g. LADM) PSM Platform Specific Model
(e.g. for PostGIS) OCL Object Constraint
Language EA Enterprise Architect (-gt UML/MDA
tool)
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Land Administration Domain Model 'Survey Package'

• Land Administration Domain Model (LADM)
• UML class diagram Lemmen and Van Oosterom, 2006
• ISO 19152 standard ISO/TC211, 2008
• Goals
• Extensible basis for IS development, based on
  Model Driven Architecture (MDA)
• LADM packages
• Core elements
• Registered Object, RRR (Rights, Responsibilities,
  Restrictions) Persons
• 5 LADM packages around core elements
• Focus on Survey Package
• Measurements of immovable objects
• Representations of objects on the cadastral map

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Object Constraint Language

• Object Constraint Language (OCL) OMG, 2006b
• UML is not capable of modelling every kind of
  constraint
• Extension of the UML diagrams to formally
  describe constraints
• No support for spatial data types and operations
• Example OCL constraint
• Based on LADM Core Elements

Written constraint the sum of all shares of a
certain right (RRR) on a specific RegisterObject
should be 1
Rights, Responsibilities and Restrictions
OCL invariant context RegisterObject inv
SumOfShares self.RRR.share-gtsum()1 or
self.RRR-gtsize()0
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Model Driven Architecture

• Model Driven Architecture OMG, 2003
• Generate information systems (semi) automatically
• Based on platform independent models
• Input Platform Independent Model (PIM)
• The LADM Survey Package UML Class Diagram ( OCL)
• Independent of implementation technology (e.g.
  PostGIS)
• E.g. classes, attributes, associations
• Output Platform Specific Models (PSM)
• The LADM 'Survey Package' PostgreSQL/PostGIS
  database
• Specific for target platform (i.e. PostGIS)
• E.g. tables, columns, primary key and check
  constraints, views, triggers

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Kadaster Project "Registration Map Quality"

• Case Study Project "Registration Map Quality"
• NL "Registratie Kaart Kwaliteit"
• Survey Measurements
• Differences between
• Measured coordinates of parcels buildings
• Adjusted (Transferred) coordinates of parcels
  buildings to fit in the cadastral map (with
  existing objects)
• Survey Measurements from Kadaster
• April 2006 - December 2007
• Analysis of Quality / Accuracy of Cadastral Map
• Graphical Precision difference max. 20 cm in
  urban area and 40 cm in rural area

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MSc Thesis ProjectObjectives and Research
Question

• Objectives
• Investigate the possibilities and limitations of
  the Model Driven Architecture (MDA) approach
• Establish an extension of the Land Administration
  Domain Model (LADM) with regard to its Survey
  Package
• Research Question

How can the Land Administration Domain Model
'Survey Package' be implemented and deployed
based on Model Driven Architecture principles,
and how can the Land Administration Domain Model
'Survey Package' be extended and improved?
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MSc Thesis ProjectSub-topics

• Evaluation of LADM 'Survey Package'
• Literature research
• Evaluation of Model Driven Architecture
• Literature research MDA Prototype experiments
• Evaluation of constraints in data modelling
• Literature research and MDA Prototype experiments
• Case Study
• Literature research and analysis of processes,
  tools and data for survey measurements
• Create MDA Prototype to implement Adapted LADM
  'Survey Package'
• MDA Prototype experiments

Compliance with MDA concepts Degree of automatic
MDA transformations Standard support and required
custom development by MDA tool (i.e. EA)
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Introduction - Summary

• Prepare an Platform Independent Model (PIM)
• Adapted LADM 'Survey Package'
• Build a MDA Prototype
• To Transform PIM into Platform Specific Model
  (PSM)
• Target PSM PostGIS
• Based on Enterprise Architect (EA)
• Create PostGIS database
• Generate DDL scripts to automatically create
  database
• Load Kadaster data
• Analyse survey measurements -gt quality/accuracy
  cadastral map
• Next Research Topics

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DETAILS on RESEARCH TOPICS

• LADM Survey Package
• Adapted LADM Survey Package
• Model Driven Architecture
• Process
• Constraints in Data Modelling
• Object Constraint Language (OCL)
• Implementation examples

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LADM Survey Package

• Recommendations for extension
• Minor errors reported
• Preliminary recommendations, e.g. SurveyProject
• Publications relevant for extension
• Observations and Measurements Open Geospatial
  Consortium, 2006b
• Survey Record Management System Lee, 2005
• Adapted LADM Survey Package
• To serve as input PIM for MDA prototype
• To be able to contain the Survey Measurement data
  (Kadaster)

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Adapted LADM 'Survey Package'PIM / UML class
diagram
SurveyProject
SurveyDocument
SurveyPoint
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Model Driven Architecture Process

• ISO19107
• GM_Point
• GM_Polygon
• Etc.

Adapted LADM 'Survey Package'
Platform Independent Model (PIM)
Platform Independent data types and operations

• MDA Transformation Rules
• Class to Table
• Generate Primary Key
• Enumeration Class
• Etc.

Platform Specific Transformation Specification
Platform Specific Model (PSM)
Platform Specific data types and operations

• PostGIS
• geometry
• POINT
• POLYGON
• Etc.

Platform Specific implementation code (e.g. DDL
DML)
Target platform PostgreSQL/PostGIS
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Object Constraint Language Implementation example
(1)

• Simple constraint for multiple attributes
• "startDate" must be
  before "endDate"

OCL invariant for multiple attribute context
SurveyProject inv startDateBeforeEndDate
self.startDate lt self.endDate
Implemented as table check constraint Table
survey_project CHECK ( start_date lt end_date )
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Object Constraint Language Implementation example
(2)

• Complex constraint for multiple classes
• Sum of "share" must
  be equal to 1
• (Not in thesis report
  -gt FIG WW Stockholm)

OCL invariant for multiple classes context
RegisterObject inv SumOfShares
self.RRR.share-gtsum()1 or self.RRR-gtsize()0
Implemented as OCL View used in database
trigger(s) create view v_ocl_sum_of_shares
as select self.oid from register_object self ,
right_responsibility_restriction rrr where
self.oid rrr.register_object.oid having
sum(rrr.share) 1
OCL View returns records that violate the OCL
invariant
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Research Topics - Summary

• Adapted LADM 'Survey Package' defined (PIM)
• MDA process from PIM to PSM
• Platform Specific Transformation Rules
• Set of MDA transformation rules, one for each PIM
  element
• Constraint (OCL) implementation examples
• Next MDA Prototype

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MDA PROTOTYPE

• MDA Prototype Setup
• Based on Enterprise Architect Sparx Systems,
  2007
• Transformations from PIM to PSM
• Result Platform Specific Model
• For Adapted LADM 'Survey Package'
• Analysis of Quality of Dutch Cadastral Map

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MDA Prototype Setup

• C Windows Forms
• 5800 lines of source code
• 90 custom developed
• demonstration

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Transformations from PIM to PSMMDA Prototype
Functionality

• First Transformation from PIM to PSM-1
• Transformation of PIM elements (UML class
  diagram)
• based on EA functionality Transformation
  Definitions
• Second Transformation from PSM-1 to PSM-2
• Fine-tuning of PSM elements (UML class diagram)
• based on MDA Prototype in C / .NET (EA SDK)
• Third Transformation from PIM OCL to PSM-2
• Initial experiments with OCL invariants
• based on MDA Prototype in C / .NET (EA SDK)
• Generate database creation scripts
• E.g. Tables, Geometry Columns, Primary, Unique
  and Foreign Key constraints, Check constraints,
  Indexes, Views

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Model Driven ArchitectureTransformation Rules

• Object Oriented UML (PIM)
• Class
• Attribute
• PIM data type
• GM_Point (ISO19107)
• GM_Polygon (ISO19107)
• Association
• Super Sub Class
• Flattening of class hierarchy branch
• Enumeration Class
• CodeList Class
• Attribute with 0.. bounds

• Relational DBMS (PSM)
• Table Primary Key constraint
• Column
• PSM data type
• POINT (PostGIS)
• POLYGON (PostGIS)
• Foreign Key Constraint
• One Table
• Inherited columns for super class attributes
• Check constraint
• 'Look-up' table
• Child table with foreign key

MDA Transformation Rule for each PIM element
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Example MDA Transformation Rule 1) Column Data
type

• PIM String GM_Point GM_MultiSurface
• PSM varchar(100) POINT MULTIPOLYGON

PIM
PSM PostGIS
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Example MDA Transformation Rule 2)
Transformation of Super and Sub Classes

• Super class SourceDocument
• Inherited by table legal_document and
  survey_document

Sub class LegalDocument
Sub class SourceDocument
PIM
PSM PostGIS
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Example MDA Transformation Rule 3)
Transformation of ltltenumerationgtgt class

• Enumeration class SurveyPointQuality
• Implemented as check constraint
  check_survey_point_quality

PIM
PSM PostGIS
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Result Platform Specific Model (PSM) Adapted
LADM 'Survey Package' in PostGIS
Platform Independent Model (PIM)
Platform Specific Model PostGIS
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Population of PostGIS Survey Measurements

• The Netherlands
• (April 2006 - Dec. 2007)
• Connection Points
• Of existing objects
• Measured Coordinate
• Transferred Coordinate
• Used for analysis of quality/accuracy of
  cadastral map

• Difference between measured and transferred
  coordinate
• Max 20 cm in Urban area
• Max. 40 cm in Rural area

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Analysis of provided dataCadastral Office

• National level 20 cm

• Difference between measured and transferred
  coordinate
• Max 20 cm in Urban area
• Max. 40 cm in Rural area

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Analysis of provided dataCadastral Section

• Outside Kadaster Norm
• Less than 95 of measurements within resp. 20 and
  40 cm

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MDA Prototype - Summary

• Custom developed MDA prototype (C)
• Based on possibilities Enterprise Architect
• Based on specified MDA transformation rules
• Automatically generates PSM from PIM
• Automatically generates DDL creation scripts
• Analysis of cadastral map accuracy performed
• Next Demonstration MDA Prototype
• Next Conclusion

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Demonstration MDA Prototype

• From PIM to PostGIS (database create scripts)
• SurveyProject, SurveyDocument SurveyPoint

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Conclusions

• Research objective reviewed
• Conclusions on MSc thesis project
• Recommendations for Future

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Research objective reviewed

• Focus on Model Driven Architecture
• "to gain experience with Model Driven
  Architecture (MDA) by performing a literature
  study, and by creating a prototype of the
  (adapted) LADM Survey Package, based on MDA
  principles".
• Performed partially
• the analysis of the quality / accuracy of
  cadastral map
• differences between measured and transferred
  coordinates of connection points
• the involvement of OCL constraints in the MDA
  prototype
• Limited amount of experiments
• the extension and improvement of the LADM 'Survey
  Package'

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Conclusions (1)

• MDA Prototype Automatically transforms PIM to PSM
• PIM -gt PSM -gt PostGIS
• complaint with MDA concept OMG, 2003
• Based on Enterprise Architect
• Solution for difference between O-O (PIM) and
  relational DBMS (PSM)
• Based on Platform specific transformation
  specification
• MDA transformation rules
• Considerable custom development required

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Conclusions (2)

• Transform and implement Geometric data types and
  operations
• Transforming geometric data types
• e.g. GM_Point, GM_LineString, GM_Polygon
• No Topology -gt future research
• Constraints assessed and classified for
  implementation
• Object Constraint Language (OCL)
• extension of UML -gt constraints that cannot be
  recorded in UML.
• Implementation by row and statement level
  triggers
• Custom development of a "transaction management
  mechanism" required

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Conclusions (3)

• Analysis of quality of the cadastral map at
  different levels
• required "graphical precision" (20/40 cm) is
  obtained at level of Cadastral Offices
• individual cases exist at cadastral section level
  need analysis

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Recommendations (1)

• Improve the standard MDA transformations in
  Enterprise Architect
• Support more complex MDA transformation rules by
  EA
• Not only the EA Software Developers Kit ( custom
  development)
• Support OCL
• Enhance the current MDA Prototype
• Aimed at changes to existing target databases
• Support additional MDA transformation rules

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Recommendations (2)

• Build MDA Transformation Tool based on XMI
• Independent of commercially available tool
• Based on XMI (input/output) OMG, 2005
• Variation of MDA transformation rules for UML and
  OCL
• Further research into combination of MDA, OCL,
  Geometry, and Topology
• Other geometric data types and operations
• Topological data types, structures and operations

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Recommendations (3)

• Extend the OCL with spatial definitions
• Spatial data types and operations
• Platform independent level e.g. ISO19107
• Platform specific level e.g. ISO/IEC 13249
  SQL/MM
• Extend the LADM 'Survey Package'
• Resolution of errors and improvements (from MSc
  thesis report)
• Publications on survey measurement related areas
  Ingvarsson, 2005, Lee, 2005, Open Geospatial
  Consortium, 2006b.

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Recommendations (4)

• Further analysis of quality of the Cadastral Map
• Outliers in the data
• Which sections are Urban and which are Rural?
• Cadastral Sections with less than 95 within 40
  cm range
• Implement improvements with regard to Survey
  Measurement Handling
• Currently based on different and separated
  applications
• Not all data is preserved (digitally and
  centrally)
• Recommended Permanent storage in an integrated
  structured database with constraint validation
  and handling
• Possible result improving the (less accurate)
  cadastral map with (more accurate) measurements
  in stead of the reverse

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Sources

• MSc Thesis MDA Prototype source
• http//www.rgi-otb.nl/geoinfoned/mda
• http//www.janvanbennekom.nl/mscthesis.html
• FIG Working Week 2008, Stockholm
• The Model Driven Architecture Approach Applied to
  the Land Administration Domain Model Version 1.1
  - with Focus on Constraints Specified in the
  Object Constraint Language
• http//www.fig.net/pub/fig2008/papers/ts01e/ts01e_
  01_hespanha_etal_2962.pdf
• Future articles
• Currently planning sub-sequent article MDA/OCL

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Discussion

• Thank you for your attention
• Next Discussion

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BACKUP
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OCL Example (1)

• Constraint for one attribute
• "name" must be in
  uppercase

OCL invariant for attribute context
CadastralMunicipality inv nameUppercase
self.name self.name.toUpper()
Implemented as table check constraint Table
cadastral_municipality CHECK ( name upper(name)
)
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Implementation of ConstraintsRow, Statement,
Transaction level

• Example Transaction
• Group of insert, update, delete statements
• SurveyProject, SurveyDocument, SurveyPoint

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1st phase free network adjustment

• Various measurements of one (1) point
• Local and/or Dutch RijksDriehoek spatial
  reference system
• Create one (1) Measured coordinate
• Input 2nd phase adjustment

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2nd phase control point constraint network
adjustment

• Convert measured coordinate to fit into the
  cadastral map
• Result Transferred coordinate
• In cadastral map

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Example MDA Transformation Rule 2) Column
Cardinality

• Column errors of type ProjectMessage
• With cardinality 0..
• Implemented as child table errors_survey_project

PSM PostGIS
PIM
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MDA Prototype SetupEnterprise Architect

• Based on Enterprise Architect
• EA UML modelling tool
• PIM Adapted LADM 'Survey Package'
• PSM e.g. PostgreSQL/PostGIS
• OCL support is limited in EA
• Limited validation / no transformation
  implementation
• EA supports MDA transformation
• EA Transformation Definitions
• EA Software Developers Kit
• Aimed at custom development

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Example MDA Transformation Rule 5)
Transformation of ltltCodeListgtgt class

• CodeList class SurveyDocumentType
• Implemented as look-up table codelist_surveydocume
  nttype

PIM
PSM PostGIS
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Implementation of Constraints

• SQL standard ISO/IEC, 2003
• Assertions
• Sub selects in base table check constraints
• Suitable, but not possible/available

SQL Assertion create assertion amount_of_survey_po
ints Check (not exists (select from
v_ocl_amount_of_survey_points))
SQL sub select in base table check
constraint ALTER TABLE survey_document ADD
CONSTRAINT amount_of_survey_points CHECK (not
exists (select count(spt.source_oid) from
survey_point spt where oid spt.source_oid
having not (count(spt.source_oid) 0 or
count(spt.source_oid) gt 2) ) )
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Open Source Tools

• PostgreSQL / PostGIS database
• http//www.postgresql.org http//postgis.refract
  ions.net
• uDig visualisation of the geographic information
• http//udig.refractions.net/
• 7.5 million records provided by Kadaster

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Kadaster Project "Registration Map Quality"

• Handling of Survey Measurements
• 1st phase free network adjustment
• Input various survey measurements of one point
• Output one Measured Coordinate
• 2nd phase control point constraint network
  adjustment
• Input Measured Coordinate
• Output Transferred Coordinates for Parcels and
  buildings on cadastral map
• Survey Measurements are "fitted in" the cadastral
  map

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Quality of cadastral map

• Difference Measured and Transferred Coordinate
• i.e. before and after 2nd phase adjustments
• Graphical Precision max. 20 cm in urban 40 cm
  in rural area
• Kadaster Norm Graphical Precision valid for 95
  of survey measurements

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Analysis of provided dataCadastral Municipality

• Difference between measured and transferred
  coordinate
• Max 20 cm. in Urban area
• Max. 40 cm. in Rural area

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Constraints in Data modellingImplementation
possibilities in target PSM

• RDBMS standard provided functionality, e.g.
• mandatory columns (i.e NOT NULL)
• primary key constraint
• unique key constraint
• foreign key constraint
• Base table Check constraints

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Constraints in Data modellingImplementation
possibilities in target PSM

• Alternative Table triggers using OCL Views
• Row level firing for each record
• Statement level firing for a group of records
  for one table
• Some (more complex) constraints require triggers
  at Transaction Level
• For example the "SumOfShares" constraint
• SQL standard
• SQL assertion
• Sub-select statements in check-constraints
• Transaction Management Mechanism
• Handling records for multiple tables
• Requires a custom development

Not available
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MDA Prototype Setup

• C Windows Forms
• 5800 lines of source code
• 90 custom developed
• Input
• Platform
• Independent Model
• Output PSM
• Platform
• Specific Model

PIM
PSM
Adapted LADM 'Survey Package'
Target platform PostgreSQL/PostGIS
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Population of PostGISParcels and Buildings

• Province of Utrecht

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Population of PostGISCadastral Office,
Municipalities, Sections

• The Netherlands

Section K
Municipality Houten
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