Perhaps you should try some spelling variations:
"blending theory" » "bending theory", "binding theory", "breeding theory"
"bounded theory" » "bounds theory", "bounded theories", "grounded theory6"
"blended theory" » "extended theory", "blended query", "blended shore"
"grounded theory" » "ground theory", "founded 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 ((("bounded theory") OR ((("blended theory") OR ("blending theory")))))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"grounded theory\") or (((\"bounded theory\") or (((\"blended theory\") OR (\"blending theory\"))))))".
• Removing quotes may allow a broader search: (( grounded theory ) or ((( bounded theory ) or ((( blended theory ) OR ( blending theory )))))).
• Adding a wildcard symbol may retrieve word variants: (("grounded theory") or ((("bounded theory") or ((("blended theory") OR ("blending theory"))))))*.