Perhaps you should try some spelling variations:
"classical mechanisms" » "classical mechanistic", "classical mechanical", "physical mechanisms", "classical mechanistics", "classical mechanicals"
"chemical mechanical" » "chemical mechanisms", "thermal mechanical", "chemo mechanical"
"classical mechanism" » "classical mechanistic", "classical mechanical", "physical mechanism"

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