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:Consistent with previous reports (al-Khodairy et al., 1995; Seufert et al., 1995; Tanaka et al., 1999; Biggins et al., 2001), our data showed that Smt3 and Ubc9 have pivotal functions during mitosis.
Category: