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:…grasslands suggests that ‘‘pyric herbivory’’ (grazing in conjunction with fire) and the interaction of natural fires and free-roaming herbivores creates a natural and dynamic grassland mosaic which is beneficial to biodiversity (Engle et al. 2008; Fuhlendorf et al. 2008; Little et al. 2013).
Category: