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:Therefore, differences between our results and those from rodent studies may reflect species differences as previously noted for the amygdalostriatal (Fudge et al., 2002, 2004) and amygdala-CeN paths (Fudge and Tucker, 2009).
Category: