Perhaps you should try some spelling variations:
estimation algorithms » estimation algorithm, optimization algorithms, optimisation algorithm
modified learning » mobile learning, modified caging
modified lighting » modified caging
method algorithm » mom algorithm
learning method » learning methods, graining methods, learning emotion

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( modified learning method algorithm ) or ( modified lighting estimation algorithms ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( modified learning method algorithm ) OR ( modified lighting estimation algorithms )).
• Adding a wildcard symbol may retrieve word variants: (( modified learning method algorithm ) or ( modified lighting estimation algorithms ))*.