BLL – Linguistic Linked Open Data Edition


The Bibliography of Linguistic Literature (BLL) is one of the most comprehensive linguistic bibliographies worldwide. It covers general linguistics with all its neighboring disciplines and subdomains as well as English, German and Romance linguistics. The BLL dates back as far as 1971 and, as of November 2017, lists circa 460.000 bibliographic references. Furthermore, the BLL provides a hierarchically categorized thesaurus of domain-specific index terms in German and English. The BLL Thesaurus comprises more than 7.900 subject terms.

The BLL and the BLL Thesaurus have been published and developed by the University Library Frankfurt, Germany (Universitätsbibliothek J. C. Senckenberg). Since 2013, the BLL Thesaurus has also been applied in the context of the Linguistik portal. Recently, a new application scenario has emerged in the process of connecting the Linguistik portal and the Linguistic Linked Open Data (LLOD) cloud. A Linked Open Data edition of the BLL Thesaurus enables the linking to other terminology repositories within the cloud and thus the connection between the Linguistik portal and the LLOD.

The development of the LOD edition of the Thesaurus as well as the integration of the LLOD resources within the Linguistik portal is a collaborative project of the University Library and the Applied Computational Linguistics (ACoLi) lab at the Goethe University Frankfurt. The project is supported by the German Research Foundation (DFG).

LOD edition

  • BLL-Thesaurus represents the original thesaurus in SKOS format, converted in a fully automated manner. The hierarchical structure is expressed by means of skos:broader.
  • BLL-Ontology comprises an ontological model of the BLL-Thesaurus. The SKOS representation was manually revised, reassessed and remodeled. The hierarchical relations are expressed by means of rfds:subClassOf.
  • BLL-Index links the BLL bibliographic entries with the corresponding index terms (in other words, it defines the bibliographic entries as instances of the ontological classes representing the BLL subject terms). BLL-Index includes only freely available bibliographic records i.e. entries published before 2007.
The ontological remodeling is completed for the thesaurus branches Syntax, Morphology, Lexicology and Phonology. The BLL Ontology is linked to the Reference Model of the Ontologies of Linguistic Annotations (OLiA).
  • OLIA-BLL-Link represents an ontology that implements subClassOf relationships between the BLL Ontology and the OLiA Reference Model.

The LOD edition of the BLL Thesaurus is released under a Creative Commons Attribution license CC-BY CC-BY Logo. The BLL-Thesaurus, BLL-Ontology and BLL-Index are available as a static data dump, the Linking Model (OLIA-BLL-Link) can be accessed via the OLiA homepage.

Versions and updates

Since the BLL Thesaurus reflects the ongoing development in the field of linguistics it evolves over time. This happens mainly by addition of new index terms, but occasional deletions are not completely ruled out.

The development of the LOD edition of the BLL Thesaurus, on the other hand, is strictly downward compatible so that existing concepts are never deleted but only marked as deprecated.

While the BLL-Thesaurus is updated on a monthly basis, the Ontology (BLL-Ontology) and the Linking Model (OLIA-BLL-Link) are updated only if needed. Significant changes of or additions to the ontological structure are documented via owl:versionInfo.


Name Description URI Download
BLL-Ontology Manually created OWL model of the BLL-Thesaurus
BLL-Thesaurus Automatically converted SKOS version of the BLL-Thesaurus
BLL-Index Mapping of BLL subject terms to BLL bibliographic records
OLIA-BLL-Link Manually created linking between the BLL Ontology and OLiA Reference Model

Via content negotiation, we offer different file formats according to the specification in the HTTP header. For the BLL-Ontology, BLL-Thesaurus and BLL-Index following mime types are supported: text/turtle, application/n-triples, application/rdf+xml.