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

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