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:…in general, with the positive effects reported in other studies with regard to self-management programs, which were similar to the prob-
lem-focused approach of this study (Birk et al., 2004; Brody et al., 2002, 2005; Dahlin-Ivanoff, 2000; Dahlin-Ivanoff et al., 2002; Eklund et al., 2004).
Category: