Perhaps you should try some spelling variations:
research theories » research theory, research themes, research topics
research studies » research study
research series » research services, research service, research summaries

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: imiscoe ((((research series) OR (research studies))) OR (research theories)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "imiscoe ((((research series) OR (research studies))) or (research theories))".
• Adding a wildcard symbol may retrieve word variants: imiscoe ((((research series) OR (research studies))) or (research theories))*.