Perhaps you should try some spelling variations:
"defensive feedback" » "effective feedback", "affective feedback"
"deceptive feedback" » "descriptive feedback", "derivative feedback", "perception feedback"
"receive feedback" » "receiving feedback", "corrective feedback", "effective 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 ("receive feedback"))) OR ("deceptive feedback")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"defensive back\") or (((((\"defensive feedback\") OR (\"receive feedback\"))) or (\"deceptive feedback\"))))".
• Removing quotes may allow a broader search: (( defensive back ) or ((((( defensive feedback ) OR ( receive feedback ))) or ( deceptive feedback )))).
• Adding a wildcard symbol may retrieve word variants: (("defensive back") or ((((("defensive feedback") OR ("receive feedback"))) or ("deceptive feedback"))))*.