Evaluate the collective function of references cited together in a given text segment.
Classify their combined role into one of the following categories: 'method', 'background', or 'result'.

Text:Despite the inconsistencies in the literature, CVP of 8 mmHg or greater (1, 2, 4) and up to 15 mmHg (14) has been advocated as end points of fluid resuscitation with some success, but these treatments are part of Bbundled care[ (i.
Category: