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:…cortical organization is well documented in the human cerebrum, particularly in the perisylvian speechlanguage regions (leftward) (LeMay 1976, 1999; Galaburda et al. 1978; Hepper et al. 1991; Foundas et al. 1995; Shapleske et al. 1999; Naidich et al. 2001; Knaus et al. 2006; Hamilton et al. 2007).
Category: