Perhaps you should try some spelling variations:
"article and nonlinear mechanical" » "article and nonlinear mechanics", "article and nonlinear dynamical"
"article and nonlinear chemical" » "article and nonlinear dynamical", "article and nonlinear numerical", "article and nonlinear optical"

You may be able to get more results by adjusting your search query.

• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"article and nonlinear chemical\") OR (\"article and nonlinear mechanical\"))".
• Removing quotes may allow a broader search: (( article and nonlinear chemical ) OR ( article and nonlinear mechanical )).
• Adding a wildcard symbol may retrieve word variants: (("article and nonlinear chemical") OR ("article and nonlinear mechanical"))*.