Perhaps you should try some spelling variations:
"mass communications issues" » "mass communication issues", "mass communications studies", "mass communications costs", "data communications issues", "crisis communications issues"
"eu cooperation studies" » "eu cooperation series", "eu cooperation sources", "eu cooperation implies", "et cooperation studies", "2 cooperation studies", "la cooperation studies"
"_ federation history" » "_ migration history", "_ federalism history", "_ federated history"

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: "((((\"mass communications issues\") OR (\"eu cooperation studies\"))) OR (\"_ federation history\"))~".
• Removing quotes may allow a broader search: (((( mass communications issues ) OR ( eu cooperation studies ))) OR ( _ federation history ))~.
• Adding a wildcard symbol may retrieve word variants: (((("mass communications issues") OR ("eu cooperation studies"))) OR ("_ federation history"))*.