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 order to identify the venom proteins responsible for the perturbation of the blood pressure, the Scorpio maurus palmatus (Smp) venom was separated by column chromatography on Sephadex G-50 gel (Figure 2) [7,9].
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