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:For example, by using IBN-Net, DenseNet169 [13], ResNet101 [8], ResNeXt101 [31], and SE-ResNet101 [12], outperform their original versions by 0.
Category: