Perhaps you should try some spelling variations:
"u.s communications series" » "u.s communication series", "u.s communications services", "u.s communication services", "3.1 communications series", "les communications series", "nps communications series"
"class communication iraq" » "mass communication iraq", "plans communication iraq", "crisis communication iraq", "class communication iran", "class communication israel", "class communication italy"
"et cooperation history" » "et corporation history", "et federation history", "et cooperations history", "eu cooperation history", "2 cooperation 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: (((("u.s communications series") OR ("class communication iraq"))) OR ("et cooperation history"))~.
• Removing quotes may allow a broader search: (((( u.s communications series ) or ( class communication iraq ))) or ( et cooperation history ))~.
• Adding a wildcard symbol may retrieve word variants: (((("u.s communications series") or ("class communication iraq"))) or ("et cooperation history"))*.