Perhaps you should try some spelling variations:
diffusion systems » fusion system
function spaces » function systems
systems based » system based, systems fast, systems game
based tool » based two
spaces a » spaces _, spaces fp, spaces hs
a tools » a tool, _ tools

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

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