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:The ROS are known to induce substantial damage to lipids and proteins (Chandra et al. 2009). Since membranes are composed of lipids and proteins, any damage to these macromolecules could result in loss of membrane integrity. Singh and Sinha (2005) reported similar results in Brassica juncea and Gallego et al. (1996) in sunflower plants.
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