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:, 2009), Turkey (Yalcuk & Ugurlu, 2009), Australia (Huett et al., 2005; Headley et al., 2001), New Zealand (Tanner et al.
Category: