Perhaps you should try some spelling variations:
"modified robust optimization algorithmssssss" » "modified robust optimization algorithms", "modified robust optimisation algorithm"
"modified objective allocation algorithms" » "modified objective estimation algorithms", "modified objective approximation algorithms"

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"modified objective allocation algorithms\") OR (\"modified robust optimization algorithmssssss\"))~".
• Removing quotes may allow a broader search: (( modified objective allocation algorithms ) OR ( modified robust optimization algorithmssssss ))~.
• Adding a wildcard symbol may retrieve word variants: (("modified objective allocation algorithms") OR ("modified robust optimization algorithmssssss"))*.