Linguistics and Language Behavior Abstracts
The most comprehensive database for linguistics.
Academic Search Premier
Journal articles on many subjects. Good source for most topics. In this database I recommend limiting to "Scholarly (Peer Reviewed) Journals" to avoid popular magazines.
MLA International Bibliography
Choose based on what period you're investigating.
L'Annee Philologique
Ancient Greece and Rome, Tacitus. Despite the title, this database is not in French.
International Medieval Bibliography (IMB)
Iter: Gateway to the Middle Ages and Renaissance
Two databases that cover all aspects of the medieval period. Go to the Advanced Search screen to limit to English or German. Warning: The WFU Full Text Options is flaky with these two databases. If you cannot find the full text on the first try, try again by searching the ZSR catalog for the book or journal title.
Historical Abstracts
European History, 1450-present
Indo-European Etymological Dictionaries Online
Includes Proto-Germanic and Old Frisian, as well as other Indo-European sub-families.