Perhaps you should try some spelling variations:
classical schemes » classical themes, classical sciences, classical schools
classical scheme » classical theme, classical science, classical school
classic scheme » class scheme, classic science, basic scheme

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 schemes) OR (classic scheme))) OR (classical scheme)) linear.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((classical schemes) OR (classic scheme))) or (classical scheme)) linear".
• Adding a wildcard symbol may retrieve word variants: ((((classical schemes) OR (classic scheme))) or (classical scheme)) linear*.