Watch out for variant spellings of names of works, characters, etc.
In MLA and other databases, frequently English-language articles use the original language name for a work. Example: La Seine était rouge instead of The Seine was Red.
Use a * to cut off a word at its stem, e.g. paris* will retrieve Paris, Parisian
If you can't use a star to search for spelling variants, use OR
france OR french
In Historical Abstracts, you can limit your search to the historical period being written about. This is only possible in the advanced search.