Perhaps you should try some spelling variations:
research theories » research theory, research topics, research three
rescue research » residue research, rescue search, resource research
research series » research services, research studies, research service
research themes » research trends, research theory

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: "\"((\\"rescue research series\\") or (\\"rescue ((research theories) OR (research themes))\\"))\"".
• Removing quotes may allow a broader search: (( rescue research series ) or ( rescue ((research theories) OR (research themes)) )).