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:This has subsequently been identified in
human cases of staphylococcal infection (Arias et al., 2008; Quinn et al., 2009; Toh et al., 2007), as well as in the LEADER Program for 2007 (Mendes et al., 2008).
Category: