Perhaps you should try some spelling variations:
augmentation techniques » segmentation techniques, imputation techniques
limitation techniques » imputation techniques, mitigation techniques, segmentation techniques
co limitation » food limitation, _ limitations
gas sensor » gas sensors
based co » based code, based no2, based two

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (( learning-gas sensor augmentation techniques ) or ( learning-based co limitation techniques ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( learning-gas sensor augmentation techniques ) OR ( learning-based co limitation techniques )).
• Adding a wildcard symbol may retrieve word variants: (( learning-gas sensor augmentation techniques ) or ( learning-based co limitation techniques ))*.