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