Perhaps you should try some spelling variations:
product learning » production learning, productive learning, product planning
project learning » project planning, project defining, project running
adults learning » agents learning
adult earnings » adult hearing, adult eating

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