Perhaps you should try some spelling variations:
"communicated diseases" » "communicated disease", "communicable diseases", "communicable disease"
"complicated diseases" » "complex diseases"
"mediated diseases" » "related diseases", "medical diseases", "related disease"
"complicated cases" » "complicated acutes", "complicated chapters", "complicated griefs"
"complicated case" » "complicated acute", "complicated chapter", "complicated grief"

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