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:In order to test the role of HOCI in the degradation of MeHg and EtHg by the MPO-H202-CI- system, aminecontaining compounds (R-NH2) capable of rapidly reacting with this species (Slivka et al. 1980; Dallegri et al. 1985) were used.
Category: