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:Previously reported naive-state hPSCs can be propagated in an LIF-dependent state in a manner akin to that of mESCs using a cocktail of small molecules (Gafni et al., 2013; Chan et al., 2013; Theunissen et al., 2014; Valamehr et al., 2014;Ware et al., 2014; Duggal et al., 2015).
Category: