Perhaps you should try some spelling variations:
"resource research series" » "resources research series", "resource search series", "source research series", "resource research services", "resource research theories", "resource research studies"
"tissue research series" » "issues research series", "pressure research series", "disease research series", "tissue research services", "tissue research theories", "tissue research studies"

Try widening your search to All Fields.

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: (("tissue research series") OR ("resource research series")).
• Removing quotes may allow a broader search: (( tissue research series ) or ( resource research series )).
• Adding a wildcard symbol may retrieve word variants: (("tissue research series") or ("resource research series"))*.