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:This is the case of the endangered giant panda (Ailuropoda melanoleuca), which is considered a global icon of biodiversity conservation (Liu et al., 2001; Loucks et al., 2001; Mackinnon and De Wulf, 1994).
Category: