To find general reference sources, start with our Online Reference Shelf to find online collections of reference sources on every subject and in every language.
See also the German, Austria and Switzerland research guide by Sue Collins, CMU History Liaison.
Biographical Sources (literary and non-literary):
Literary Reference Tools:
While the following selection of Carnegie Mellon University database subscriptions will primarily point you to English language sources, many contain German language sources if you search using German [most do not allow limit by language, but use it if available].