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:Additionally, the results surpassed the numbers of 8–9 h of “lying down” reported in two studies on persons with moderate or severe OSAS [21, 22] and the 9 h and 55 min of sedentary time previously reported in patients with OSAS and obesity receiving CPAP treatment [23].
Category: