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