Perhaps you should try some spelling variations:
"certified network optimization algorithms" » "certified network optimisation algorithm", "certified network estimation algorithms", "certified network estimation algorithm", "verified network optimization algorithms"
"modified notion approximation algorithms" » "modified network approximation algorithms", "modified time approximation algorithms", "modified one approximation algorithms"

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• Performing a fuzzy search may retrieve terms with similar spellings: (("certified network optimization algorithms") OR ("modified notion approximation algorithms"))~.
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