Perhaps you should try some spelling variations:
"defensive feedback" » "effective feedback", "receive feedback", "affective feedback"
"deceptive feedback" » "descriptive feedback", "receive feedback", "derivative feedback"
"defensive back" » "defensive war", "defensive bee"

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: (("defensive back") OR ((("defensive feedback") OR ("deceptive feedback")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"defensive back\") or (((\"defensive feedback\") OR (\"deceptive feedback\"))))".
• Removing quotes may allow a broader search: (( defensive back ) or ((( defensive feedback ) OR ( deceptive feedback )))).
• Adding a wildcard symbol may retrieve word variants: (("defensive back") or ((("defensive feedback") OR ("deceptive feedback"))))*.