Perhaps you should try some spelling variations:
"modified objective estimation algorithms" » "modified objective estimation algorithm", "modified objective optimization algorithms", "modified objective optimisation algorithm", "modified objective allocation algorithms"
"modified model selection algorithm" » "modified model solution algorithm", "modified model estimation algorithm", "modified model reduction algorithm", "modified market selection algorithm", "modified male selection algorithm"

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

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