Perhaps you should try some spelling variations:
"state evolutionary sources" » "state evolutionary source", "state evolutionary forces", "state evolutionary studies", "state revolutionary sources", "states evolutionary sources", "stage evolutionary sources"
"last revolution sources" » "last resolution source", "last evolution resources", "last pollution sources", "post revolution sources", "next revolution sources", "silent revolution sources"

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"last revolution sources\") OR (\"state evolutionary sources\"))".
• Removing quotes may allow a broader search: (( last revolution sources ) OR ( state evolutionary sources )).
• Adding a wildcard symbol may retrieve word variants: (("last revolution sources") OR ("state evolutionary sources"))*.