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:As illustrated in Figure 1(a, b), it transforms CNNs such as VGG [38] and C3D [43] with fc layers at the end of the convolutional networks, meanwhile it also converts CNNs such as ResNet [20] and DenseNet [22] with conv and global average pooling layers at the end, as depicted in Figure 1(c, d).
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