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

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: (( function systems based tool ) OR ( ((diffusion system) OR (diffusion systems)) using tools ))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( function systems based tool ) or ( ((diffusion system) OR (diffusion systems)) using tools ))~".
• Adding a wildcard symbol may retrieve word variants: (( function systems based tool ) or ( ((diffusion system) OR (diffusion systems)) using tools ))*.