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:…isolated I. schwarzi survived significantly better than isolated Z. angusticollis (BS = 53.4, p < 0.001; BS = 7.0,
p = 0.008, respectively; Z. angusticollis data from Rosengaus et al. 1998) surviving approximately 1 and 4 days longer following low and high dose exposures, respectively (Figure 2A).
Category: