Perhaps you should try some spelling variations:
"complicated diseases" » "complicated cases", "complex diseases", "mediated diseases"
"communication state" » "communication style", "communicating state", "communication strategy"
"communicate state" » "communicate strategy", "communicating state", "communicate make"

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: (("communicable diseases") OR ((("complicated diseases") OR ((("communicate state") OR ("communication state")))))).
• Removing quotes may allow a broader search: (( communicable diseases ) or ((( complicated diseases ) or ((( communicate state ) or ( communication state )))))).
• Adding a wildcard symbol may retrieve word variants: (("communicable diseases") or ((("complicated diseases") or ((("communicate state") or ("communication state"))))))*.