Perhaps you should try some spelling variations:
"modified rough approximation algorithm" » "modified rough approximation algorithms", "modified rough approximations algorithm", "modified one approximation algorithm"
"modified quantile optimization algorithms" » "modified quantile optimisation algorithm", "modified quantile estimation algorithms", "modified quantile estimation algorithm", "modified quadratic optimization algorithms", "modified static optimization algorithms", "modified adaptive optimization 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 rough approximation algorithm") OR ("modified quantile optimization algorithms"))~.
• Removing quotes may allow a broader search: (( modified rough approximation algorithm ) or ( modified quantile optimization algorithms ))~.
• Adding a wildcard symbol may retrieve word variants: (("modified rough approximation algorithm") or ("modified quantile optimization algorithms"))*.