Perhaps you should try some spelling variations:
diffusion systems » fusion system
function systems » equation systems, function spaces, fusion system
systems based » system based, systems fast, systems game
systems usage » systems game
based tools » based tool, coated tools

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

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