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