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

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