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:General symptoms of anxiety and depression were evaluated by the Hamilton Anxiety Rating Scale (HARS; Hamilton, 1959) and the Hamilton Rating Scale for Depression (HRSD; Hamilton, 1960), administered by IEs in accordance with the Structured Interview Guide for the Hamilton Anxiety and Depression Rating Scale (SIGH-A and SIGH-D, respectively; Shear, Vander Bilt, & Rucci, 2001; Williams, 1988), and the self-report Beck Depression Inventory (BDI-II; Beck, Steer, & Brown, 1996) and Beck Anxiety Inventory (BAI; Beck, Epstein, Brown,& Steer, 1988; Beck& Steer, 1990; Steer, Ranieri, Beck, & Clark, 1993).
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