Perhaps you should try some spelling variations:
estimation algorithms » estimation algorithm, optimization algorithms, optimisation algorithm
solution algorithms » solution algorithm, evolution algorithm, convolution algorithms
notion estimation » motion estimation
modified passive » modified adaptive
passive solution » positive solutions, saline solution

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

• If you are trying to use Boolean operators, they must be ALL CAPS: (( modified passive solution algorithms ) OR ( modified notion estimation algorithms ))~.
• Adding a wildcard symbol may retrieve word variants: (( modified passive solution algorithms ) or ( modified notion estimation algorithms ))*.