Perhaps you should try some spelling variations:
imputation techniques » implantation technique, augmentation techniques, segmentation techniques
inhalation technique » floatation technique, implantation technique, inhaler technique
co inhalation » _ inhalation
based no2 » based n
based co » based code, based two, based _

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