Since 2013, the thesaurus of the Bibliography of Linguistic Literature (BLL Thesaurus) has been applied in the context of the Linguistik
portal, a hub for linguistically relevant information. Several consecutive projects focus on the modeling of the BLL Thesaurus as ontology and its linking to terminological repositories in the Linguistic Linked Open Data (LLOD) cloud. Those mappings facilitate the connection between the Linguistik portal and the cloud. In the paper, we describe the current efforts to establish interoperability between the language-related index terms and repositories providing language identifiers for the web of Linked Data. After an introduction of Lexvo and Glottolog, we outline the scope, the structure, and the peculiarities of the BLL Thesaurus. We discuss the challenges for the design of scientifically plausible language classification and the linking between divergent classifications. We describe the prototype of the linking model and propose pragmatic solutions for structural or conceptual conflicts. Additionally, we depict the benefits from the envisaged interoperability - for the Linguistik portal, and the Linked Open Data Community in general
