Perhaps you should try some spelling variations:
22knowledge economy » knowledge ecology, knowledge economy's
knolwedge economy » knowledge economy's, knowledge ecology
knowlege economy » knowledge economy's, knowledge ecology

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: %((((((((22knowledge economy) OR (knowlege economy))) OR (knolwedge economy))) OR (((knowledge economic) OR (knowledge economies))))) OR (knowledge economy))%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%((((((((22knowledge economy) OR (knowlege economy))) or (knolwedge economy))) or (((knowledge economic) or (knowledge economies))))) or (knowledge economy))%22".
• Adding a wildcard symbol may retrieve word variants: %((((((((22knowledge economy) OR (knowlege economy))) or (knolwedge economy))) or (((knowledge economic) or (knowledge economies))))) or (knowledge economy))%22*.