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:Cravings were measured using the Alcohol Urge Questionnaire (AUQ) (Bohn et al. 1995), the Obsessive Compulsive Drinking Scale (OCDS) (Anton et al. 1995), the Questionnaire on Smoking UrgesBrief (QSU-B) (Cox et al. 2001), and a smoking Visual Analogue Scale (S-VAS) on which scores range from 1 to 10…
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