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:We (Mays and Schirillo, 2005) previously showed that light flashes affect auditory processing in a directional hearing illusion (Hari, 1995; Hari and Kiesilä, 1996).
Category: