Perhaps you should try some spelling variations:
"modified df optimization algorithms" » "modified df optimisation algorithm", "modified df estimation algorithms", "modified df estimation algorithm", "modified _ optimization algorithms", "modified qoe optimization algorithms", "modified _ optimisation algorithms", "modified adam optimization algorithms", "modified bi1 optimization algorithms"
"mobile learning method algorithm" » "mobile learning mom algorithm", "machine learning method algorithm", "mobile learning methods algorithm", "mobile graining methods algorithm", "mobile learning emotion algorithm"

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

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