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