Perhaps you should try some spelling variations:
"research professor" » "research profession", "research progresson", "research process"
"research problems" » "research process", "research program"
"research progress" » "research program"

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: (("research professor") OR ((("research projects") OR ((((("research problems") OR ("research project"))) OR ("research progress")))))).
• Removing quotes may allow a broader search: (( research professor ) or ((( research projects ) or ((((( research problems ) or ( research project ))) or ( research progress )))))).
• Adding a wildcard symbol may retrieve word variants: (("research professor") or ((("research projects") or ((((("research problems") or ("research project"))) or ("research progress"))))))*.