Perhaps you should try some spelling variations:
"communicate diseases" » "communicable diseases", "communicable disease", "communicate disabled"
"complicated diseases" » "complicated cases", "complex diseases", "mediated diseases"
"communicated disease" » "communicable disease", "communicable diseases", "communicate state"

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