Perhaps you should try some spelling variations:
imputation techniques » implantation technique, augmentation techniques, segmentation techniques
floatation technique » inhalation technique, implantation technique, truncation technique
no2 floatation » _ floatation
based no2 » based co, based n
based nde » based anode, based code, based 3d

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 no2 floatation technique ) OR ( learning-based nde imputation techniques ))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( learning-based no2 floatation technique ) OR ( learning-based nde imputation techniques ))".
• Adding a wildcard symbol may retrieve word variants: (( learning-based no2 floatation technique ) OR ( learning-based nde imputation techniques ))*.