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

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