Perhaps you should try some spelling variations:
"modified multiobjective optimization algorithm" » "modified multiobjective optimization algorithms", "modified multiobjective optimisation algorithm", "modified multiobjective estimation algorithm"
"modified invasive evolution algorithm" » "modified invasive solution algorithm", "modified invasive evolutionary algorithm", "modified invasive convolution algorithms", "modified invasive ventilation algorithm", "modified passive evolution 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 multiobjective optimization algorithm") or ("modified invasive evolution algorithm"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("modified multiobjective optimization algorithm") OR ("modified invasive evolution algorithm")).
• Removing quotes may allow a broader search: (( modified multiobjective optimization algorithm ) or ( modified invasive evolution algorithm )).
• Adding a wildcard symbol may retrieve word variants: (("modified multiobjective optimization algorithm") or ("modified invasive evolution algorithm"))*.