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:The results in the two groups after 8 weeks were similar (p > 0.05) and comparable to the normal values found in the specialized literature at 8 weeks after surgery (Andrews et al., 1996; Greis et al., 2002; Maffiuletti, 2010).
Category: