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