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