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:Previous studies have shown that the intracellular correlates of SRFPs are dominated by GABA-A receptordependent IPSPs (IPSCs in voltage-clamp recordings) in both CA3 and CA1 pyramidal neurons (Wu et al., 2002, 2005a).
Category: