Perhaps you should try some spelling variations:
operation instrumentation » applications instrumentation, therapy instrumentation, modern instrumentation
instrumentation theory » instrumentation methods, instrumentation https, instruction theory
theory division » theory decision, theory revision, theorems division
basics linear » basic linear, based linear, basics clear
class linear » less linear, mass linear, class library

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

• Performing a fuzzy search may retrieve terms with similar spellings: operation instrumentation theory division ((basics linear) or (class linear))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: operation instrumentation theory division ((basics linear) OR (class linear)).
• Adding a wildcard symbol may retrieve word variants: operation instrumentation theory division ((basics linear) or (class linear))*.