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

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