Perhaps you should try some spelling variations:
"residue research theories" » "residue research theory", "residue research themes", "residue research topics", "residues research theories", "residual research theories", "rescue research theories"
"resource research series" » "resources research series", "source research series", "resource search series", "resource research services", "resource research service", "resource research summaries"
"tissue research studies" » "tissue research study", "issues research studies", "pressure research studies", "disease research studies"
"residue research series" » "residues research series", "residual research series", "rescue research series", "residue research services", "residue research service", "residue research summaries"
"tissue research series" » "tissue research services", "tissue research service", "tissue research summaries", "issues research series", "pressure research series", "disease research series"

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