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