Perhaps you should try some spelling variations:
"modified coverage approximation algorithms" » "modified average approximation algorithms"
"modified learning emotion algorithm" » "mobile learning emotion algorithm", "modified caging emotion algorithm", "modified learning evolution algorithm", "modified learning estimation algorithm", "modified learning predation algorithm", "modified learning method algorithm"

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (("modified learning emotion algorithm") or ("modified coverage approximation algorithms"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("modified learning emotion algorithm") OR ("modified coverage approximation algorithms")).
• Removing quotes may allow a broader search: (( modified learning emotion algorithm ) or ( modified coverage approximation algorithms )).
• Adding a wildcard symbol may retrieve word variants: (("modified learning emotion algorithm") or ("modified coverage approximation algorithms"))*.