Perhaps you should try some spelling variations:
"certified network approximation algorithm" » "certified network approximation algorithms", "verified network approximation algorithm"
"modified allocation optimisation algorithm" » "modified allocation optimization algorithm", "modified allocation optimization algorithms", "modified allocation estimation algorithm", "modified allocation estimation 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: "((\"certified network approximation algorithm\") OR (\"modified allocation optimisation algorithm\"))~".
• Removing quotes may allow a broader search: (( certified network approximation algorithm ) OR ( modified allocation optimisation algorithm ))~.
• Adding a wildcard symbol may retrieve word variants: (("certified network approximation algorithm") OR ("modified allocation optimisation algorithm"))*.