Perhaps you should try some spelling variations:
augmentation techniques » segmentation techniques, imputation techniques
reduction technique » reduction techniques, truncation technique
no2 augmentation » data augmentation
two reduction » h2o2 reduction, _ reduction
based no2 » based co, based n
based two » based tool, based co

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