Perhaps you should try some spelling variations:
imputation techniques » implantation technique, augmentation techniques, segmentation techniques
simulation techniques » mitigation techniques, segmentation techniques, inhalation technique
n simulation » _ simulation, a simulation, _ simulations
based no2 » based co
based n » based _, based k, 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 imputation techniques ) or ( learning-based n simulation techniques ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( learning-based no2 imputation techniques ) OR ( learning-based n simulation techniques )).
• Adding a wildcard symbol may retrieve word variants: (( learning-based no2 imputation techniques ) or ( learning-based n simulation techniques ))*.