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:Comparable results were found in studies on teleosts (Carassius auratus, e.g. Salas et al. 1996a, b; Rodrƒ±ÃÅguez et al. 2002a; Portavella et al. 2002; Broglio et al. 2005; DuraÃÅn et al. 2008).
Category: