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