In order for library (meta-)data to be published as linked data, it has to contain links. At the OCLC EMEA Meeting in Berlin on February 21-22, 2017, I used those slides to present how we create, ingest, store and export links to and from the metadata we create in the German National Library

1. Relations matter: Maintaining and
Publishing Links in Library Metadata
Lars G. Svensson
| 24 | Relations Matter | February 21, 20171

2. 2 | 24 | Relations Matter | February 21, 2017
On the web, users expect that there are links
leading them to the information they need
https://de.wikipedia.org/wiki/Ismar_Elbogen

3. 3 | 24 | Relations Matter | February 21, 2017
We as libraries create links all the time, e.g.
by linking titles to authority data
Composite
Description
Part
Composite
Description
Whole
Work Person
SlidecourtseytoJanaHentschke

4. 4 | 24 | Relations Matter | February 21, 2017
The links in libraries are usually only local
and only visible in the catalogue

5. | 24 | Relations Matter | February 21, 2017
Libraries must be part of a global link infra-
structure, not restricted to their own data
5
LinkingOpenDataclouddiagram2017,byAndrejsAbele,JohnP.McCrae,
PaulBuitelaar,AnjaJentzschandRichardCyganiak.http://lod-cloud.net/

6. 6 | 24 | Relations Matter | February 21, 2017
In the German National Library, we have
implemented different solutions to this
ILS
internal
format
PICA
IN OUT
Manual
cataloguing
Import:
MARC 21
ONIX
XMetaDissPlus
JATS
MARC 21
MODS
Dublin Core
Linked Data
SlidecourtseytoJanaHentschke

7. 7 | 24 | Relations Matter | February 21, 2017
In order to publish links, someone must
create them…
Photo by The Hamster Factor (CC BY-NC-ND): http://www.flickr.com/photos/disaster_area/3454110496/
<owl:AnnotationProperty rdf:about="http://d-nb.info/standards/elementset/gnd#marc21equivalent">
<rdfs:label xml:lang="de">MARC 21 Entsprechung</rdfs:label>
<rdfs:label xml:lang="en">MARC 21 equivalent</rdfs:label>
<rdfs:comment xml:lang="de">Gibt die MARC 21 Entsprechung des Elements im GND-MARC-Format wieder.</rdfs:comment>
<rdfs:comment xml:lang="en">Expresses the MARC 21 equivalent for this element in the GND MARC format.</rdfs:comment>
</owl:AnnotationProperty>
@prefix void: <http://rdfs.org/ns/void#> .
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
@prefix owl: <http://www.w3.org/2002/07/owl#> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
@prefix dcterms: <http://purl.org/dc/terms/> .
@prefix foaf: <http://xmlns.com/foaf/0.1/> .
<mx:datafield tag="153" ind2=" " ind1=" ">
<mx:subfield code="a">220.531</mx:subfield>
<mx:subfield code="y">1</mx:subfield>
<mx:subfield code="a">7</mx:subfield>
<mx:subfield code="e">220.531</mx:subfield>
<mx:subfield code="j">Paraphrasen</mx:subfield>
<mx:subfield code="9">ess=ren</mx:subfield>
</mx:datafield>
</mx:record>

8. 8 | 24 | Relations Matter | February 21, 2017
Cataloguers create links in our CBS
[...]
100 Elbogen, Ismar
375 m
400 Elbogen, Yiṣhạq Moše
400 Elbogen, Jiṣhāq Möšeh
400 Elbogen, Itamar
400 Elbogen, J.
400 Elbogen, I.
400 ʾLBWGN, Jiṣḥaq Mōšeh
400 Elbogen, Yitsḥaḳ Mosheh
400 $T01$UHebr%% ‫אלבוגן‬,‫יצחק‬‫משה‬
548 $a01.09.1874$b01.08.1943$4datx
548 1874$b1943$4datl
550 !040250989!Historiker [Ts1]$4berc
551 !943330920!Ostrzeszów [Tg1]$4ortg
551 !040420116!New York, NY [Tg1]$4orts
551 !040787044!USA [Tg1]$4ortx$Z1938
667 7
667 Maschinell verknuepft mit DBL-Retro-Titeldaten
[...]
[...]
2105 95,G03,0966
2242 |o|722667362
3000 !116446706!Elbogen, Ismar [Tp1]
3211 Der @jüdische Gottesdienst in seiner geschichtlichen
4000 Jewish liturgy : a comprehensive history / by Ismar El
4020 #11#1. Engl. ed.
4030 Philadelphia ; Jerusalem : Jewish Publ. Soc.
4030 New York ; Jerusalem : Jewish Theological Seminary o
4060 XXI, 501 S.
4062 27 cm
4201 Literaturverz. S. 461 - 473
4700 |FE|H
5050 %13+200+220+290
5100 !040216713!Gottesdienst [Ts1]
5101 !041140877!Judentum [Ts1]
[...]

9. 9 | 24 | Relations Matter | February 21, 2017
Automated processes handling digital
publications are part of the equation, too
[…]
4180 IFLA Publications ; 162
4201 Lizenzpflichtig
4233 *a*
4243 Erscheint auch als$nOnline-Ausgabe$i978-3-11-031700-8
4243 Erscheint auch als$i978-3-11-031701-5
4243 Erscheint auch als$nDruck-Ausgabe!1032799889!--Aa--: Linked data and user interaction
4256 Elektronische Reproduktion von$i9783110316926
4700 |PE|*Parallelverknüpfung wurde automatisch erstellt
5050 020$Ep$D2016-05-27
5050 020$Em$Hdnb$K0,993$D2016-05-27
5050 020$Ea$Honx$D2016-05-26
5051 $KK_A4_06_20151019_en
5052 $f570$F0,759$g530$G0,718$D2016-05-27
5100 !040064395!Bibliothek [Ts1]
5101 !1021290033!Linked Data [Ts1]
5102 !041385349!Benutzer [Ts1]
5103 !041259092!Mensch-Maschine-Kommunikation [Ts1]
5104 !041215605!Recherche [Ts1]
5105 !041323157!Suchverfahren [Ts1]
[…]
[…]
5100 !040291057!Kabbala [Ts1]
5101 !041205375!Kabbalistik [Ts1]
5102 :z Geschichte
5109 (DE-101){DE-101}
5110 !041140877!Judentum [Ts1]
5111 !04041003X!Mystik [Ts1]
5112 :z Geschichte
5119 (DE-101){DE-101}
5540 [FA]!041140877!Judentum [Ts1]
5540 [GND]!964308118!Zizit [Ts1]$K0,009$D2016-
5540 [GND]!040097994!Chassidismus [Ts1]$K0,005
5540 [GND]!041205375!Kabbalistik [Ts1]$K0,005$D
5540 [GND]!040216845!Gottesname [Ts1]$K0,004$
5540 [GND]!040216624!Gott [Ts1]$K0,004$D2016-
5540 [GND]!119235587!Yisraʾel ben Eliʿezer Baʿal S
5540 [GND]!041910117!Zohar [Tu1]$K0,003$D201
5540 [GND]!041336992!Talmud [Tu1]$K0,003$D20
5540 [GND]!11900173X!Akiba ben Joseph [Tp1]$K0
5540 [GND]!040291057!Kabbala [Ts1]$K0,615$D20
5540 [GND]!04041003X!Mystik [Ts1]$K0,300$D201
5540 [GND]!042243726!Sefirot [Ts1]$K0,016$D201
[…]

10. 10 | 24 | Relations Matter | February 21, 2017
A further source is to import links from third
parties (e. g. Wikipedia)
https://de.wikipedia.org/wiki/Ismar_Elbogen
http://d-nb.info/gnd/116446706

11. 11 | 24 | Relations Matter | February 21, 2017
The data in our CBS can be exported in
several different formats
Conversion Seriali-
sation
ILS
Data Conversion Service
Conversion
I
n
d
e
x Enrichment
Database
Wikidata
RDF
MARC 21
EntityFacts
PDF
------------
http://d-nb.info
SRU
OAI
Data Dumps
Data Shop
VIAF
Classification
Alignments
GND-ID-Lists
Slide adapted from Jana Hentschke

12. 12 | 24 | Relations Matter | February 21, 2017
MARC 21 is still a very important format
024 7 $ahttp://d-nb.info/gnd/116446706 $2uri
[…]
100 1 $aElbogen, Ismar$d1874-1943
375 $a1$2iso5218
[…]
548 $a01.09.1874-01.08.1943
$94:datx$wr$iExakte Lebensdaten
548 $a1874-1943$94:datl$wr$iLebensdaten
550 $0(DE-101)040250989
$0(DE-588)4025098-2
$0http://d-nb.info/gnd/4025098-2
$aHistoriker $94:berc
$wr$iCharakteristischer Beruf
551 $0(DE-101)943330920
$0(DE-588)4363227-0
$0http://d-nb.info/gnd/4363227-0
$aOstrzeszów $94:ortg $wr $iGeburtsort
551 $0(DE-101)040420116
$0(DE-588)4042011-5
$0http://d-nb.info/gnd/4042011-5
$aNew York, NY $94:orts $wr $iSterbeort
100 1 $0(DE-588)116446706
$0http://d-nb.info/gnd/116446706
$0(DE-101)116446706
$aElbogen, Ismar$d1874-1943$4aut
245 00$aJewish liturgy$ba comprehensive history
$cby Ismar Elbogen. [Transl. by Raymond P. Scheindlin. B
250 $a1. Engl. ed.
259 $a11
264 1$aPhiladelphia$aJerusalem$bJewish Publ. Soc.
$aNew York$aJerusalem
$bJewish Theological Seminary of America$c1993
300 $aXXI, 501 S.$c27 cm
500 $aLiteraturverz. S. 461 - 473
648 7$aGeschichte$2gnd
650 7$0(DE-588)4021671-8
$0http://d-nb.info/gnd/4021671-8
$0(DE-101)040216713
$aGottesdienst$2gnd
650 7$0(DE-588)4114087-4
$0http://d-nb.info/gnd/4114087-4
$0(DE-101)041140877$aJudentum$2gnd

13. 13 | 24 | Relations Matter | February 21, 2017
<http://d-nb.info/gnd/116446706> a gndo:DifferentiatedPerson ;
foaf:page <http://de.wikipedia.org/wiki/Ismar_Elbogen> ;
owl:sameAs <http://dbpedia.org/resource/Ismar_Elbogen> , <http://viaf.org/viaf/71500476>;
gndo:gndIdentifier "116446706" ;
gndo:oldAuthorityNumber "(DE-588a)116446706" , "(DE-588a)130915076" , "(DE-588c)7558592-3" ;
gndo:gndSubjectCategory <http://d-nb.info/standards/vocab/gnd/gnd-sc#16.1p> ;
gndo:geographicAreaCode <http://d-nb.info/standards/vocab/gnd/geographic-area-code#XA-
DXDE> ;
gndo:biographicalOrHistoricalInformation "Breslau, Univ., Phil. Diss., 1898"@de , "Dt. Historiker; Berlin;
Prof. f. jü dische Geschichte, geb. in Schildberg <Posen>"@de ;
gndo:placeOfBirth <http://d-nb.info/gnd/4363227-0> ;
gndo:placeOfDeath <http://d-nb.info/gnd/4042011-5> ;
gndo:placeOfExile <http://d-nb.info/gnd/4078704-7> ;
gndo:gender <http://d-nb.info/standards/vocab/gnd/gender#male> ;
gndo:dateOfBirth "1874-09-01"^^<http://www.w3.org/2001/XMLSchema#date> ;
gndo:dateOfDeath "1943-08-01"^^<http://www.w3.org/2001/XMLSchema#date> ;
gndo:professionOrOccupation <http://d-nb.info/gnd/4025098-2> ;
gndo:variantNameForThePerson "Elbogen, Yiṣhạq Moš e" ;
gndo:variantNameEntityForThePerson [
gndo:forename "Yiṣhạq Moš e" ;
gndo:surname "Elbogen" .
] ;
gndo:variantNameForThePerson "Elbogen, Jiṣhāq Mö š eh" ;
gndo:variantNameEntityForThePerson [
Non-libraries are more keen on the RDF
representation

14. 14 | 24 | Relations Matter | February 21, 2017
{"@context" : "http://hub.culturegraph.org.appr/entityfacts/context/v1/entityfacts.jsonld",
"@type" : "person",
"@id" : "http://d-nb.info/gnd/116446706",
"preferredName" : "Ismar Elbogen", "surname" : "Elbogen", "forename" : "Ismar",
"variantName" : [ "Yiṣhạq Moš e Elbogen", "‫אלבוגן‬ ‫משה‬ ‫יצחק‬" ],
"dateOfBirth" : "1. September 1874",
"dateOfDeath" : "1. August 1943",
"placeOfBirth" : [{ "@id" : "http://d-nb.info/gnd/4363227-0", "preferredName" : "Ostrzeszów" } ],
"placeOfDeath" : [{ "@id" : "http://d-nb.info/gnd/4042011-5", "preferredName" : "New York, NY" } ],
"professionOrOccupation" : [ {
"@id" : "http://d-nb.info/gnd/4025098-2", "preferredName" : "Historiker„ } ],
"gender" : { "@id" : "http://d-nb.info/standards/vocab/gnd/gender#male", "label" : "Mann" },
"depiction" : {
"@id" : "https://commons.wikimedia.org/wiki/Special:FilePath/Ismar_Elbogen.jpg",
},
"sameAs" :
[ { "@id" : "http://catalogue.bnf.fr/ark:/12148/cb12521261q",
"collection" : {
"abbr" : "BNF", "name" : "Bibliothèque nationale de France",
"publisher" : "Bibliothèque nationale de France", "icon" : http://www.bnf.fr/bnf_dev/icono/favicon.ico" },
{ "@id" : "http://kulturportal-west-ost.eu/persons/elbogen-ismar/",
"collection" : {
"abbr" : "OSTDEBIB", "name" : "Ostdeutsche Biographie", "publisher" : "Kulturportal West-Ost" }
},
EntityFacts offers fact sheets about persons,
places and things from the GND
http://hub.culturegraph.org.appr/entityfacts/116446706

15. | 24 | Relations Matter | February 21, 2017
The exported data is used in a plethora of
contexts
15

16. | 24 | Relations Matter | February 21, 2017
museum-digital has an interesting use of the
RDF data from the GND
16
http://www.museum-digital.de/san/index.php?t=objekt&oges=42749

17. 17 | 24 | Relations Matter | February 21, 2017
The geospatial coordinates have been
exploited by game-creators

18. 18 | 24 | Relations Matter | February 21, 2017
And EntityFacts help people find and display
authoritative facts
https://www.deutsche-digitale-bibliothek.de/entity/116446706

19. 19 | 24 | Relations Matter | February 21, 2017
So where do all those links take us?
PhotobyNicoKaiser(CC-BY):
http://www.flickr.com/photos/nicokaiser/4667377944/sizes/z/in/photostream/

20. 20 | 24 | Relations Matter | February 21, 2017
Librarians continuously create links that
often are visible only in the library catalogue
ByŠJů,WikimediaCommons,CCBY-SA3.0,https://commons.wikimedia.org/w/index.php?curid=18200682

21. 21 | 24 | Relations Matter | February 21, 2017
Libraries must be part of a global link infra-
structure, not restricted to their own data
PhotobyKIUIStaff(CCBY):http://www.flickr.com/photos/kiui/3693823005/
Library
data
Other
data
Some
data

22. 22 | 24 | Relations Matter | February 21, 2017
Third parties can enchance the data from
libraries and re-publish that information
http://www.steinheim-institut.de/see-also/query.html?text1=116446706&kategorie1=GND

23. 23 | 24 | Relations Matter | February 21, 2017
And by doing this we contribute to a global
infrastructure of well-curated facts
PicturebyDaveGray(CCBY-NC-ND):https://flic.kr/p/5TdMvq

24. 24 | 24 | Relations Matter | February 21, 2017
Because after all, everything is somehow
related to everything else!
Diagrambybenediktkoehler(CCBY-NC):https://flic.kr/p/b7wxWz