Perhaps you should try some spelling variations:
"modified orca approximation algorithms" » "modified one approximation algorithms", "modified _ approximation algorithms", "modified time approximation algorithms"
"modified learning method algorithm" » "mobile learning method algorithm", "modified caging method algorithm", "modified learning mom algorithm", "modified learning methods algorithm", "modified graining methods algorithm", "modified learning emotion algorithm"

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"modified learning method algorithm\") OR (\"modified orca approximation algorithms\"))~".
• Removing quotes may allow a broader search: (( modified learning method algorithm ) OR ( modified orca approximation algorithms ))~.
• Adding a wildcard symbol may retrieve word variants: (("modified learning method algorithm") OR ("modified orca approximation algorithms"))*.