Perhaps you should try some spelling variations:
"_ corporation biography sources" » "_ corporate biography sources", "_ reformation biography sources", "_ corporate geography sources", "_ corporation bibliography resources"
"a corporation biography series" » "a corporate biography series", "a reformation biography series", "a corporate geography series", "a corporation biography pericles", "a corporation biography sermons", "a corporation biography studies"
"_ federation biography sources" » "_ reformation biography sources", "_ federation bibliography resources", "_ federated biography sources", "_ federalism biography sources", "_ federalist biography sources"

Try widening your search to All Fields.

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: (((("_ corporation biography sources") OR ("_ federation biography sources"))) OR ("a corporation biography series")).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"_ corporation biography sources\") OR (\"_ federation biography sources\"))) or (\"a corporation biography series\"))".
• Removing quotes may allow a broader search: (((( _ corporation biography sources ) OR ( _ federation biography sources ))) or ( a corporation biography series )).
• Adding a wildcard symbol may retrieve word variants: (((("_ corporation biography sources") OR ("_ federation biography sources"))) or ("a corporation biography series"))*.