Perhaps you should try some spelling variations:
"classical mechanical" » "chemical mechanical", "physical mechanical", "statistical mechanical"
"physical mechanisms" » "physiological mechanisms"
"classical mechanism" » "classical mechanisms", "classical mechanistic", "physical mechanism"

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: (((((("physical mechanisms") OR ("classical mechanical"))) OR ("classical mechanics"))) OR ("classical mechanism")).
• Removing quotes may allow a broader search: (((((( physical mechanisms ) or ( classical mechanical ))) or ( classical mechanics ))) or ( classical mechanism )).
• Adding a wildcard symbol may retrieve word variants: (((((("physical mechanisms") or ("classical mechanical"))) or ("classical mechanics"))) or ("classical mechanism"))*.