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:To deal with the high computational complexity of 3D geometrybased matching techniques, existing works typically adopt a pre-processing stage to quickly identify a small set of candidates which are later refined with geometry-based matching [3, 11, 7].
Category: