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