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

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 learning))) OR (((((product learning) OR (product planning))) OR (project learning))))%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%((((adults learning) or (adult learning))) or (((((product learning) OR (product planning))) or (project learning))))%22".
• Adding a wildcard symbol may retrieve word variants: %((((adults learning) or (adult learning))) or (((((product learning) OR (product planning))) or (project learning))))%22*.