Perhaps you should try some spelling variations:
"modified adam approximation algorithm" » "modified adam approximation algorithms", "modified _ approximation algorithm", "modified one approximation algorithm", "modified time approximation algorithm", "modified df approximation algorithm", "modified near approximation algorithm"
"modified parameters optimization algorithms" » "modified parameter optimization algorithms", "modified parameter estimation algorithms", "modified parameters optimisation algorithm", "modified parameters estimation algorithms", "modified parameters estimation algorithm"

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 adam approximation algorithm") or ("modified parameters optimization algorithms"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("modified adam approximation algorithm") OR ("modified parameters optimization algorithms")).
• Removing quotes may allow a broader search: (( modified adam approximation algorithm ) or ( modified parameters optimization algorithms )).
• Adding a wildcard symbol may retrieve word variants: (("modified adam approximation algorithm") or ("modified parameters optimization algorithms"))*.