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