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:Other proteins, including synaptotagmin (Matthew et al., 1981) and SV2 (Buckley and Kelly, 1985; Bajjalieh et al., 1992), are components of both small clear synaptic vesicles and large, dense-core
vesicles (Kelly, 1993).
Category: