Perhaps you should try some spelling variations:
"coupled theory" » "coupling theory", "coupled thermo", "coupled memory"
"founded theory" » "grounded theory6", "founding theory", "founded where"
"grounded theory" » "ground theory", "bounded 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: (("grounded theory") OR ((("founded theory") OR ("coupled theory")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"grounded theory\") or (((\"founded theory\") OR (\"coupled theory\"))))".
• Removing quotes may allow a broader search: (( grounded theory ) or ((( founded theory ) OR ( coupled theory )))).
• Adding a wildcard symbol may retrieve word variants: (("grounded theory") or ((("founded theory") OR ("coupled theory"))))*.