Perhaps you should try some spelling variations:
"psychological economics" » "physiological economics", "ecological economics", "psychological dynamics", "technological economics", "psychology economics"
"psychological economist" » "psychological contract", "psychological concept", "psychological content"
"psychological economic" » "ecological economic", "technological economic", "psychology economic"

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