Perhaps you should try some spelling variations:
nonlinear physical » nonlinear physics, nonlinear chemical, nonlinear optical
nuclear physical » nuclear physics, nuclear optical
nuclear medical » nuclear medicine, nuclear material

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: (((( particle AND nuclear physical ) OR ( particle AND nuclear medical ))) OR ( particle AND nonlinear physical )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(((( particle and nuclear physical ) OR ( particle and nuclear medical ))) or ( particle and nonlinear physical ))".
• Adding a wildcard symbol may retrieve word variants: (((( particle and nuclear physical ) OR ( particle and nuclear medical ))) or ( particle and nonlinear physical ))*.