Perhaps you should try some spelling variations:
"modified sphere estimation algorithms" » "modified sphere estimation algorithm", "modified sphere optimization algorithms", "modified sphere optimisation algorithm", "modified pose estimation algorithms"
"modified objective optimized algorithms" » "modified objective optimized algorithm", "modified objective optimizer algorithms", "modified objective optimization algorithms", "modified objective optimal algorithms"

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 sphere estimation algorithms") or ("modified objective optimized algorithms"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("modified sphere estimation algorithms") OR ("modified objective optimized algorithms")).
• Removing quotes may allow a broader search: (( modified sphere estimation algorithms ) or ( modified objective optimized algorithms )).
• Adding a wildcard symbol may retrieve word variants: (("modified sphere estimation algorithms") or ("modified objective optimized algorithms"))*.