Perhaps you should try some spelling variations:
"collinear particles theory" » "colloidal particles theory", "colliding particles theory", "linear particle theory", "collinear particles through"
"nonlinear particle theory" » "linear particle theory", "nonlinear price theory", "nuclear particle theory"
"nonlinear material theory" » "nonlinear materials theory", "nonlinear matrix theory", "nonlinear media theory"
"collider particle theory" » "colloidal particle theory", "colliding particle theory", "colloid particle theory"
"nonlinear partial theory" » "nonlinear spatial theory", "nonlinear partial memory", "nonlinear partial tears"

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 particle theory") OR ((("collinear particles theory") OR ("collider particle theory"))))))) OR ("nonlinear material theory")).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"nonlinear partial theory\") or (((\"nonlinear particle theory\") or (((\"collinear particles theory\") OR (\"collider particle theory\"))))))) or (\"nonlinear material theory\"))".
• Removing quotes may allow a broader search: (((( nonlinear partial theory ) or ((( nonlinear particle theory ) or ((( collinear particles theory ) OR ( collider particle theory ))))))) or ( nonlinear material theory )).
• Adding a wildcard symbol may retrieve word variants: (((("nonlinear partial theory") or ((("nonlinear particle theory") or ((("collinear particles theory") OR ("collider particle theory"))))))) or ("nonlinear material theory"))*.