Perhaps you should try some spelling variations:
"eastern european sources." » "eastern europe sources.", "east european sources.", "eastern european studies.", "eastern european southern.", "eastern european journal."
"eastern european series." » "eastern europe series.", "east european series.", "eastern european studies.", "eastern european cities.", "eastern european society."
"western europe sources." » "eastern europe sources."

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

• Performing a fuzzy search may retrieve terms with similar spellings: (((("eastern european sources.") OR ("western europe sources."))) or ("eastern european series."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("eastern european sources.") OR ("western europe sources."))) OR ("eastern european series.")).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"eastern european sources.\") OR (\"western europe sources.\"))) or (\"eastern european series.\"))".
• Removing quotes may allow a broader search: (((( eastern european sources. ) OR ( western europe sources. ))) or ( eastern european series. )).
• Adding a wildcard symbol may retrieve word variants: (((("eastern european sources.") OR ("western europe sources."))) or ("eastern european series."))*.