Perhaps you should try some spelling variations:
"learning-based robust imputation techniques" » "learning-based robust implantation technique", "learning-based robust augmentation techniques", "learning-based robust segmentation techniques", "learning-based roms imputation techniques", "learning-based trust imputation techniques"
"learning-based a simulation technique" » "learning-based a inhalation technique", "learning-based a implantation technique", "learning-based a mitigation techniques", "learning-based _ simulation technique", "learning-based k simulation technique", "learning-based n simulation technique"

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 a simulation technique") or ("learning-based robust imputation techniques"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("learning-based a simulation technique") OR ("learning-based robust imputation techniques"))*.
• Removing quotes may allow a broader search: (( learning-based a simulation technique ) or ( learning-based robust imputation techniques ))*.