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:Neuropsychological testing
Participants completed the World Health Organization (WHO)/NIMH/UCLA international battery (Maj et al. 1993, 1994) consisting of measures designed to assess the following skills: motor speed and fine motor control, verbal and visual memory, attention, and cognitive…
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