Perhaps you should try some spelling variations:
limitation techniques » imputation techniques, mitigation techniques, augmentation techniques
floatation technique » inhalation technique, implantation technique, imputation techniques
two floatation » _ floatation
ko2 limitation » co limitation, food limitation
based two » based tool, based co
based ko2 » based no2, based co, based k

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 two floatation technique ) or ( learning-based ko2 limitation techniques ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( learning-based two floatation technique ) OR ( learning-based ko2 limitation techniques )).
• Adding a wildcard symbol may retrieve word variants: (( learning-based two floatation technique ) or ( learning-based ko2 limitation techniques ))*.