Perhaps you should try some spelling variations:
"eastern european sources." » "eastern europe sources.", "eastern european studies.", "eastern european southern.", "eastern european journal.", "fastern european sources."
"east european series." » "east european studies.", "east european cities.", "east european society.", "fast european series."
"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 ("east european series."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("eastern european sources.") OR ("western europe sources."))) OR ("east european series.")).
• Removing quotes may allow a broader search: (((( eastern european sources. ) or ( western europe sources. ))) or ( east european series. )).
• Adding a wildcard symbol may retrieve word variants: (((("eastern european sources.") or ("western europe sources."))) or ("east european series."))*.