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