Perhaps you should try some spelling variations:
research professor » research profession, research process, research processes
research progress » research project
research projects » research project
research problems » research project
research program » research project

You may be able to get more results by adjusting your search query.

• The words AND, OR and NOT may confuse the search; try adding quotes: "\"((\\"research professor\\") or (((((\\"research progress\\") or (\\"research projects\\"))) or (\\"((research problems) OR (research program))\\"))))\"".
• Removing quotes may allow a broader search: (( research professor ) or ((((( research progress ) or ( research projects ))) or ( ((research problems) OR (research program)) )))).