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:On the other hand, energy crops like RCG grown on rewetted peatlands may facilitate both CH4 and N2O emissions, as aerenchyma tissue present in RCG can mediate the transport of CH4 and N2O from soil to the atmosphere (Askaer et al. 2011; Jørgensen et al. 2012).
Category: