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:Twenty-two publications report values for EUS [11,26,28,30,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56] and 7 report for TAUS [24,27,57,58,59,60,61], however the overall patient numbers between groups were similar (1857 patients for TAUS and 1875 for EUS).
Category: