Perhaps you should try some spelling variations:
"eu cooperation studies" » "eu cooperation series", "eu cooperation sources", "eu cooperation implies", "et cooperation studies", "2 cooperation studies", "la cooperation studies"
"mars communication iraq" » "mass communication iraq", "mass communications iraq", "markets communication iraq", "mars communication iran", "mars communication israel", "mars communication italy"
"its migration history" » "u.s migration history", "us migration history", "cs migration history"

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: (((("mars communication iraq") OR ("eu cooperation studies"))) OR ("its migration history"))~.
• Removing quotes may allow a broader search: (((( mars communication iraq ) or ( eu cooperation studies ))) or ( its migration history ))~.
• Adding a wildcard symbol may retrieve word variants: (((("mars communication iraq") or ("eu cooperation studies"))) or ("its migration history"))*.