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:2011), a death rate that becomes large when organisms are large (Law et al. 2009; Blanchard et al. 2009) or a fixed size spectrum in the range x > a (Benoît and Rochet 2004).
Category: