Perhaps you should try some spelling variations:
"learning-based a implantation technique" » "learning-based a floatation technique", "learning-based a inhalation technique", "learning-based _ implementation technique", "learning-based _ implantation technique", "learning-based k implantation technique", "learning-based 3d implantation technique"
"learning-based n imputation techniques" » "learning-based n augmentation techniques", "learning-based n segmentation techniques", "learning-based n floatation technique", "learning-based _ computation techniques", "learning-based _ reputation techniques", "learning-based _ imputation techniques", "learning-based k imputation techniques", "learning-based no2 imputation 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 n imputation techniques") OR ("learning-based a implantation technique"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"learning-based n imputation techniques\") OR (\"learning-based a implantation technique\"))".
• Removing quotes may allow a broader search: (( learning-based n imputation techniques ) OR ( learning-based a implantation technique )).
• Adding a wildcard symbol may retrieve word variants: (("learning-based n imputation techniques") OR ("learning-based a implantation technique"))*.