Perhaps you should try some spelling variations:
"research professor" » "research profession", "research processes", "search processor"
"research prozess" » "research progress", "research propels", "research processes"
"research process" » "research progress", "research projects", "research problems"

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