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

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