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