Perhaps you should try some spelling variations:
"ecological theory" » "psychological theory", "ecolocal theory", "ecoethical theory", "ecopolitical theory"
"sociological theory" » "sociolocal theory", "socioethical theory", "sociopolitical theory", "biological theory"
"logical theory" » "local theory", "ethical theory", "political theory"

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: (("sociological theory") OR ((("logical theory") OR ("ecological theory")))).
• Removing quotes may allow a broader search: (( sociological theory ) or ((( logical theory ) or ( ecological theory )))).
• Adding a wildcard symbol may retrieve word variants: (("sociological theory") or ((("logical theory") or ("ecological theory"))))*.