Perhaps you should try some spelling variations:
"communicate disabled" » "communicate discover", "communicate listen", "communicated disease"
"complicated diseases" » "complicated cases", "complex diseases", "complicated case"
"mediated diseases" » "related diseases", "related disease"
"medical diseases" » "tropical diseases", "viral diseases"

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