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:Five of the seven studies showed a significant difference (p < 0.05) in favour of microTESE (Amer et al., 2000; Okada et al., 2002; Ramasamy et al., 2005; Colpi et al., 2009; Ghalayini et al., 2011).
Category: