Perhaps you should try some spelling variations:
virtual library » virtual laboratory
visual library » visual literacy, visual binary, visual lidar
gson library » own library, town library
open library » opencv library
von linear » non linear, von linearen

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: %22theory AND ((((von linear) OR (((visual library) OR (virtual library))))) OR (((gson library) OR (((open library) OR (chosen library))))))%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%22theory and ((((von linear) or (((visual library) OR (virtual library))))) or (((gson library) or (((open library) or (chosen library))))))%22".
• Adding a wildcard symbol may retrieve word variants: %22theory and ((((von linear) or (((visual library) OR (virtual library))))) or (((gson library) or (((open library) or (chosen library))))))%22*.