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

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 research series ))) OR ((( rescue research theories ) OR ( resource research theories ))))) OR ( residue research service )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(((((( tissue research series ) or ( pressure research 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 research series ))) or ((( rescue research theories ) OR ( resource research theories ))))) or ( residue research service ))*.