Perhaps you should try some spelling variations:
"structural fluctuations" » "structural equations", "structural alterations", "statistical fluctuations"
"structural functional" » "structure function"
"structure functions" » "structure function"

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: (("structural fluctuations") OR ((("structural functional") OR ("structure functions")))).
• Removing quotes may allow a broader search: (( structural fluctuations ) or ((( structural functional ) or ( structure functions )))).
• Adding a wildcard symbol may retrieve word variants: (("structural fluctuations") or ((("structural functional") or ("structure functions"))))*.