Perhaps you should try some spelling variations:
22knowledge economy » knowlege economy, knolwedge economy
knowledge economy's » knowledge economies, knowlege economy, knowledge ecologies
knowledge economic » knowledge economies
knowledge ecology » knowledge technology, knowledge sociology, knowledge ecologies

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 (((knowledge economy's) OR (knowledge ecology))))) OR (knowledge economic))) OR (knowledge economy))%22.
• Adding a wildcard symbol may retrieve word variants: %((((((22knowledge economy) or (((knowledge economy's) or (knowledge ecology))))) or (knowledge economic))) or (knowledge economy))%22*.