Perhaps you should try some spelling variations:
mitigation techniques » imputation techniques
reduction techniques » reduction technique, imputation techniques
closed reduction » model reduction
based closed » based code, based cross
n mitigation » _ mitigation, _ litigation
based n » based _, based k, based no2

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 closed reduction techniques ) or ( learning-based n mitigation techniques ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( learning-based closed reduction techniques ) OR ( learning-based n mitigation techniques )).
• Adding a wildcard symbol may retrieve word variants: (( learning-based closed reduction techniques ) or ( learning-based n mitigation techniques ))*.