Perhaps you should try some spelling variations:
"independent studies in policy economic." » "independent states in policy economic.", "independent audits in policy economic.", "independent study in policy economic."
"Independent studies in ecological economics." » "Independent studies in technological economics."

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (("Independent studies in ecological economics.") OR ("independent studies in policy economic."))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"Independent studies in ecological economics.\") OR (\"independent studies in policy economic.\"))".
• Removing quotes may allow a broader search: (( Independent studies in ecological economics. ) OR ( independent studies in policy economic. )).
• Adding a wildcard symbol may retrieve word variants: (("Independent studies in ecological economics.") OR ("independent studies in policy economic."))*.