Perhaps you should try some spelling variations:
biography sources » bibliography resources
biography series » biography pericles, biography sermons, biography studies
rand federation » ad federation, road federation, based federation
rag federation » road federation, a federation, la federation
a corporation » _ corporation, a corporate

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: (( ((rand federation) OR (rag federation)) ((biography series) OR (biography sources)) ) OR ( a corporation ((biography series) OR (biography sources)) ))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( ((rand federation) or (rag federation)) ((biography series) OR (biography sources)) ) or ( a corporation ((biography series) OR (biography sources)) ))*".