Perhaps you should try some spelling variations:
"research professor" » "research profession", "research processes", "research prozess"
"research problems" » "research program"
"research progress" » "research program"
"research process" » "research program", "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 project"))) OR ((((("research problems") OR ("research projects"))) OR ("research progress")))))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"research professor\") or (((((\"research process\") OR (\"research project\"))) or (((((\"research problems\") or (\"research projects\"))) or (\"research progress\"))))))".
• Removing quotes may allow a broader search: (( research professor ) or ((((( research process ) OR ( research project ))) or ((((( research problems ) or ( research projects ))) or ( research progress )))))).
• Adding a wildcard symbol may retrieve word variants: (("research professor") or ((((("research process") OR ("research project"))) or ((((("research problems") or ("research projects"))) or ("research progress"))))))*.