Perhaps you should try some spelling variations:
"east european southern." » "east europe southern.", "east europe northern.", "fast european southern."
"eastern european sources." » "eastern europe sources.", "western europe sources.", "eastern european studies.", "eastern european series.", "eastern european journal.", "fastern european sources."
"fastern europe sources." » "eastern europe sources.", "western europe sources.", "eastern europe's sources."

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: (((("eastern european sources.") OR ("east european southern."))) OR ("fastern europe sources."))~.
• Removing quotes may allow a broader search: (((( eastern european sources. ) or ( east european southern. ))) or ( fastern europe sources. ))~.
• Adding a wildcard symbol may retrieve word variants: (((("eastern european sources.") or ("east european southern."))) or ("fastern europe sources."))*.