Perhaps you should try some spelling variations:
"modified stochastic optimization algorithms" » "modified stochastic optimisation algorithm", "modified stochastic estimation algorithms", "modified stochastic estimation algorithm"
"defined network approximation algorithms" » "designed network approximation 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: (("defined network approximation algorithms") OR ("modified stochastic optimization algorithms"))~.
• Removing quotes may allow a broader search: (( defined network approximation algorithms ) or ( modified stochastic optimization algorithms ))~.
• Adding a wildcard symbol may retrieve word variants: (("defined network approximation algorithms") or ("modified stochastic optimization algorithms"))*.