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 ((((("communicate state") OR ("communication state"))) OR ("complicated diseases")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"communicable diseases\") or (((((\"communicate state\") OR (\"communication state\"))) or (\"complicated diseases\"))))".
• Removing quotes may allow a broader search: (( communicable diseases ) or ((((( communicate state ) OR ( communication state ))) or ( complicated diseases )))).
• Adding a wildcard symbol may retrieve word variants: (("communicable diseases") or ((((("communicate state") OR ("communication state"))) or ("complicated diseases"))))*.