Perhaps you should try some spelling variations:
"ecological economics" » "economics economics"
"political economic" » "political ecology"
"policy economic" » "policy economics", "policy macroeconomic"

Try widening your search to All Fields.

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