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:modeled in terms of CA, including the Belousov–Zhabotinsky (BZ) reaction [1,2], the Turing system [3], a precipitating BZ system for computation of Voronoi diagram [4,5], and
Category: