Perhaps you should try some spelling variations:
"modified network approximation algorithm" » "modified network approximation algorithms", "certified network approximation algorithm", "defined network approximation algorithm", "modified near approximation algorithm"
"modified caging optimization algorithms" » "modified caging optimisation algorithm", "modified caging estimation algorithms", "modified caging estimation algorithm", "modified staffing optimization 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 network approximation algorithm") or ("modified caging optimization algorithms"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("modified network approximation algorithm") OR ("modified caging optimization algorithms")).
• Removing quotes may allow a broader search: (( modified network approximation algorithm ) or ( modified caging optimization algorithms )).
• Adding a wildcard symbol may retrieve word variants: (("modified network approximation algorithm") or ("modified caging optimization algorithms"))*.