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:We have found no strain differences in magnitude of NaCl responses, which is consistent with results of previous studies using the B6 and 129 strains (Gannon and Contreras, 1993; Ninomiya et al., 1996) and implies that gustatory neural responses of B6 and 129 mice to sodium-containing MSG, IMP and GMP are not affected by differential responses to sodium.
Category: