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:This approach, however, entails a 11 to 20% risk of intraperitoneal bleeding [11, 12, 22], and pediatric experience in this area is limited to small case series [10, 13, 15, 16, 21, 23, 24].
Category: