Perhaps you should try some spelling variations:
"nps communications series" » "nps communication series", "nps communications services", "nps communication services", "les communications series", "u.s communications series", "vos communications series"
"nets communication issues" » "nets community issues", "nets communication india", "nets communication united", "lea's communication issues", "mass communication issues", "c's communication issues"
"its cooperation history" » "its corporation history", "its federation history", "city cooperation history", "et cooperation history"

Try widening your search to All Fields.

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

• Performing a fuzzy search may retrieve terms with similar spellings: (((("nps communications series") or ("nets communication issues"))) or ("its cooperation history"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("nps communications series") OR ("nets communication issues"))) OR ("its cooperation history")).
• Removing quotes may allow a broader search: (((( nps communications series ) or ( nets communication issues ))) or ( its cooperation history )).
• Adding a wildcard symbol may retrieve word variants: (((("nps communications series") or ("nets communication issues"))) or ("its cooperation history"))*.