Perhaps you should try some spelling variations:
diffusion systems » fusion system
function systems » equation systems, function spaces, fusion system
function system » fusion system
systems using » system using, symptoms using, systems usage
based two » based tool, based co

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