Perhaps you should try some spelling variations:
"researching professional" » "research professional", "teaching professional", "learning professional"
"research professionals" » "research professional", "resource professionals", "resources professionals"
"research professor" » "research profession", "research processes", "research prozess"
"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 process"))) OR ((("research professionals") OR ("researching professional")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"research professor\") or (\"research process\"))) or (((\"research professionals\") OR (\"researching professional\"))))".
• Removing quotes may allow a broader search: (((( research professor ) or ( research process ))) or ((( research professionals ) OR ( researching professional )))).
• Adding a wildcard symbol may retrieve word variants: (((("research professor") or ("research process"))) or ((("research professionals") OR ("researching professional"))))*.