Perhaps you should try some spelling variations:
"modified objective optimization algorithm" » "modified multiobjective optimization algorithm", "modified objective optimization algorithms", "modified objective optimisation algorithm", "modified objective estimation algorithm"
"model learning solution algorithm" » "model learning evolution algorithm", "model learning convolution algorithms", "model learning evolutionary algorithm", "model learning convolution algorithm", "model learning emotion algorithm", "mobile learning solution algorithm"

Try widening your search to All Fields.

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (("modified objective optimization algorithm") or ("model learning solution algorithm"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("modified objective optimization algorithm") OR ("model learning solution algorithm")).
• Removing quotes may allow a broader search: (( modified objective optimization algorithm ) or ( model learning solution algorithm )).
• Adding a wildcard symbol may retrieve word variants: (("modified objective optimization algorithm") or ("model learning solution algorithm"))*.