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