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

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 projects"))) OR ((((("research problems") OR ("research project"))) OR ("research program")))))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"research professor\") or (((((\"research process\") OR (\"research projects\"))) or (((((\"research problems\") or (\"research project\"))) or (\"research program\"))))))".
• Removing quotes may allow a broader search: (( research professor ) or ((((( research process ) OR ( research projects ))) or ((((( research problems ) or ( research project ))) or ( research program )))))).
• Adding a wildcard symbol may retrieve word variants: (("research professor") or ((((("research process") OR ("research projects"))) or ((((("research problems") or ("research project"))) or ("research program"))))))*.