Perhaps you should try some spelling variations:
"founded theory" » "grounded theory", "grounded theory6", "founding theory"
"blended theory" » "extended theory", "blending theory", "blended query"
"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: (("founded theory") OR ((("bounds theory") OR ("blended theory")))).
• Removing quotes may allow a broader search: (( founded theory ) or ((( bounds theory ) or ( blended theory )))).
• Adding a wildcard symbol may retrieve word variants: (("founded theory") or ((("bounds theory") or ("blended theory"))))*.