Perhaps you should try some spelling variations:
nonlinear vortices » nonlinear optics, nonlinear lattices, nonlinear forces
nonlinear material » nonlinear materials, nonlinear matrix, nonlinear media
vortices theory » particles theory, vortex theory, services theory
material theory » materials theory
partial theory » particle theory, spatial theory, particles theory

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: (((( nonlinear partial theory ) OR ( nonlinear vortices theory ))) OR ( nonlinear material theory )).
• Adding a wildcard symbol may retrieve word variants: (((( nonlinear partial theory ) or ( nonlinear vortices theory ))) or ( nonlinear material theory ))*.