Perhaps you should try some spelling variations:
"defined network optimization algorithm" » "defined network optimization algorithms", "defined network optimisation algorithm", "defined network estimation algorithm"
"modified model solution algorithm" » "modified model evolution algorithm", "modified model convolution algorithms", "modified model evolutionary algorithm", "modified male solution algorithm", "modified model solutions algorithm", "modified nodal solution algorithm", "modified model selection 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: (("modified model solution algorithm") OR ("defined network optimization algorithm"))~.
• Removing quotes may allow a broader search: (( modified model solution algorithm ) or ( defined network optimization algorithm ))~.
• Adding a wildcard symbol may retrieve word variants: (("modified model solution algorithm") or ("defined network optimization algorithm"))*.