Perhaps you should try some spelling variations:
function systems » equation systems, function spaces, fusion system
functions spaces » function spaces, functions based
systems based » system based, systems fast, systems game
spaces using » space using, gases using, paper using
based co » based code, based no2, based two

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (( function systems based co ) or ( functions spaces using tools ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( function systems based co ) OR ( functions spaces using tools )).
• Adding a wildcard symbol may retrieve word variants: (( function systems based co ) or ( functions spaces using tools ))*.