The CCARH databases use the work designations found in the sources which are encoded. This normally includes the language, spelling, and punctuation of the published text. The identifying information may be supplemented with additional information from later catalogues or online work-lists, as explained under Sources.
Naming conventions for musical works are functional but they are not entirely standardized from one repertory to another. Cataloguing conventions continue to evolve.
If your first search is unsuccessful, consider these possibilities:
Some useful sources for decoding the contents of collected
Anna Harriet Heyer, Historical Sets, Collected Editions, and Monuments of Music (1957; 1969; 1989);
Collected Editions, Historical Series and Sets and Monuments of Music: A Bibliography by George Robert Hill and Norris L. Stephens (Fallen Leaf Reference Books in Music, No. 14; 1997);
relevant work lists in The New Grove Dictionary of Music and Musicians (1980; rev. edn., 2000).