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