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:Other clinical scales used were the Hamilton Depression Rating Scale (HDRS) [34], the Young Mania Rating Scale (YMRS) [72], the severity subscale of the Clinical Global Impression Scale (CGI) [25], the Global Assessment of Functioning Scale (GAF) [19], and the Premorbid Adjustment Scale (PAS) [10].
Category: