Perhaps you should try some spelling variations:
imputation techniques » implantation technique, augmentation techniques, segmentation techniques
simulation technique » inhalation technique, implantation technique, mitigation techniques
cross simulation » carlo simulation, mri simulation
based cross » based roms, based access, based closed
based tool » 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-based tool imputation techniques ) or ( learning-based cross simulation technique ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( learning-based tool imputation techniques ) OR ( learning-based cross simulation technique )).
• Adding a wildcard symbol may retrieve word variants: (( learning-based tool imputation techniques ) or ( learning-based cross simulation technique ))*.