Here are a few types of libraries and some foreign-language translations:
Library - 1) A place where books, manuscripts, musical scores, or other literary and artistic materials are kept for use but not for sale. 2) Such a collection itself. 3) An institution for the custody or administration of such collections.
German: Bibliothek, often Staatsbibliothek to designate one of many German state libraries.
Archive - A library where public institutional records are preserved, as well as documents or other materials of historical value.
Special Collections Library - A library that holds rare books, manuscripts, artworks, documents, recordings, and works in unusual formats that require specialists' knowledge to administer and curate and that has facilities and procedures to protect the collections from damage and theft.
Here are a few additional terms related to musical sources and their study.
Argument - 1) A reason given in proof or rebuttal. 2) A coherent series of reasons offered; 3) An abstract or summary of a literary work. 4) The subject of a literary work.
Primary source - Dating from the historical period under discussion.
Secondary source - A source that presents information that originally appeared elsewhere. Secondary sources usually present analysis, interpretation, and evaluation of the material discussed.
Iconography - The study of visual representations of people and objects, e.g. musicians and musical instruments, in paintings, sculpture, reliefs, mosaics, etc.
You may find it helpful to refer to this list of Common Terms Used in German Publications and Thematic Indices compiled by music catalogers at Yale University.