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:Recently, 3D-CNNs have been widely used for various 3D data analysis tasks such as 3D detection or classification [39, 31, 29], semantic segmentation [7, 32] and reconstruction [44, 6, 45, 15, 49].
Category: