Perhaps you should try some spelling variations:
mitigation techniques » imputation techniques
reduction technique » reduction techniques, truncation technique
closed reduction » model reduction
two mitigation » _ mitigation, error mitigation
based closed » based code, based cross
based two » based tool, based co

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( learning-based two mitigation techniques ) or ( learning-based closed reduction technique ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( learning-based two mitigation techniques ) OR ( learning-based closed reduction technique )).
• Adding a wildcard symbol may retrieve word variants: (( learning-based two mitigation techniques ) or ( learning-based closed reduction technique ))*.