Perhaps you should try some spelling variations:
"learning-based 3d imputation techniques" » "learning-based 3d implantation technique", "learning-based 3d augmentation techniques", "learning-based 3d segmentation techniques", "learning-based 3d simulation techniques", "learning-based _ imputation techniques", "learning-based co imputation techniques", "learning-based k imputation techniques"
"learning-based twode floatation techniques" » "learning-based twode floatation technique", "learning-based twode inhalation technique", "learning-based twode mitigation techniques", "learning-based anode floatation techniques", "learning-based code floatation techniques", "learning-based two floatation techniques"

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 3d imputation techniques") or ("learning-based twode floatation techniques"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("learning-based 3d imputation techniques") OR ("learning-based twode floatation techniques"))*.
• Removing quotes may allow a broader search: (( learning-based 3d imputation techniques ) or ( learning-based twode floatation techniques ))*.