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:…of a relatively larger area or volume (Alidaee et al., 2009; Beard et al., 2006; Bertuccelli et al., 2004; Gancet et al., 2005; Kovacina et al., 2002; Kuiper and Nadjm-Tehrani, 2006; Lawrence et al., 2004; Merino et al., 2006; Parunak et al., 2005; Richards et al., 2002; Sauter et al., 2005).
Category: