Perhaps you should try some spelling variations:
productive learning » predictive learning, proactive learning, production learning
22adult learning » adult learning, adults learning, adt learning
project defining » project definition, project planning, project design

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: %((22adult learning) OR (((productive learning) OR (project defining))))%22.
• Adding a wildcard symbol may retrieve word variants: %((22adult learning) or (((productive learning) or (project defining))))%22*.