Perhaps you should try some spelling variations:
"modified allocation estimation algorithms" » "modified allocation optimization algorithms", "modified motion estimation algorithms", "modified allocation estimation algorithm", "modified allocation optimisation algorithm"
"modified passive optimized algorithms" » "modified passive optimized algorithm", "modified passive optimizer algorithms", "modified passive optimization algorithms", "modified adaptive optimized algorithms"

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 optimized algorithms") OR ("modified allocation estimation algorithms"))~.
• Removing quotes may allow a broader search: (( modified passive optimized algorithms ) or ( modified allocation estimation algorithms ))~.
• Adding a wildcard symbol may retrieve word variants: (("modified passive optimized algorithms") or ("modified allocation estimation algorithms"))*.