Perhaps you should try some spelling variations:
"resource research theories" » "resources research theories", "resource search theories", "source research theories", "resource research theory", "resource research themes", "resource research topics"
"rescue research theories" » "rescue research theory", "rescue research themes", "rescue research topics", "rescue search theories", "issue research theories", "response research theories"
"pressure release series" » "press release series", "press releases series", "pressure release stories", "pressure release studies", "pressure release sources"
"residue research service" » "residues research service", "residual research service", "resident research service", "residue search service", "residue research overview", "residue research section"
"tissue research series" » "issues research series", "pressure research series", "disease research series", "tissue research services", "tissue research studies", "tissue research summaries"

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