Perhaps you should try some spelling variations:
"grounded theory6" » "grounded theorie", "grounded theory8.1", "grounded theories"
"founded theory" » "founding theory", "founded where", "sound theory"
"coupled theory" » "coupling theory"
"coupled memory" » "coupled membrane"

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 ("grounded theory6"))) OR ((((("coupled theory") OR ("coupled thermo"))) OR ("coupled memory")))))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"grounded theory\") or (((((\"founded theory\") OR (\"grounded theory6\"))) or (((((\"coupled theory\") or (\"coupled thermo\"))) or (\"coupled memory\"))))))".
• Removing quotes may allow a broader search: (( grounded theory ) or ((((( founded theory ) OR ( grounded theory6 ))) or ((((( coupled theory ) or ( coupled thermo ))) or ( coupled memory )))))).
• Adding a wildcard symbol may retrieve word variants: (("grounded theory") or ((((("founded theory") OR ("grounded theory6"))) or ((((("coupled theory") or ("coupled thermo"))) or ("coupled memory"))))))*.