Perhaps you should try some spelling variations:
"eu cooperation studies" » "eu cooperation series", "eu cooperation sources", "eu cooperation implies", "2 cooperation studies", "la cooperation studies", "de cooperation studies"
"its colonization songs" » "its colonization still", "its colonization work", "its decolonization notes", "anti colonization songs", "jews colonization songs", "mars colonization songs"
"et cooperation still" » "et cooperation scale", "et cooperation state", "et cooperation series", "et cooperations still", "2 cooperation still", "de cooperation still"

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: (((("et cooperation still") OR ("eu cooperation studies"))) OR ("its colonization songs"))~.
• Removing quotes may allow a broader search: (((( et cooperation still ) or ( eu cooperation studies ))) or ( its colonization songs ))~.
• Adding a wildcard symbol may retrieve word variants: (((("et cooperation still") or ("eu cooperation studies"))) or ("its colonization songs"))*.