Perhaps you should try some spelling variations:
learning courier » learning course, learning curve, learning curves
courier services » tourism services, under services
open learning » open burning
survey series » surveys series
curve series » course series, care series, surveys series

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: (( open learning ((curve series) OR (survey series)). ) OR ( a learning courier services. ))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( open learning ((curve series) OR (survey series)). ) or ( a learning courier services. ))~".
• Adding a wildcard symbol may retrieve word variants: (( open learning ((curve series) OR (survey series)). ) or ( a learning courier services. ))*.