Perhaps you should try some spelling variations:
"modified network optimization algorithm" » "modified network optimization algorithms", "modified network optimisation algorithm", "modified network estimation algorithm", "certified network optimization algorithm", "defined network optimization algorithm", "modified near optimization algorithm"
"machines learning methods algorithm" » "machine learning methods algorithm", "active learning methods algorithm", "mapping learning methods algorithm", "machines nursing methods algorithm"

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: (("machines learning methods algorithm") OR ("modified network optimization algorithm"))~.
• Removing quotes may allow a broader search: (( machines learning methods algorithm ) or ( modified network optimization algorithm ))~.
• Adding a wildcard symbol may retrieve word variants: (("machines learning methods algorithm") or ("modified network optimization algorithm"))*.