Perhaps you should try some spelling variations:
"articles and nonlinear physical" » "articles and nonlinear physics", "articles and nonlinear chemical", "articles and nonlinear optical"
"articles and nuclear physical" » "articles and nuclear medical", "articles and nuclear optical"

Try widening your search to All Fields.

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