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