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:Preclinical work by Dyrby et al. (2013) highlights the benefits of such strong gradients and the first results from the Connectome scanner (McNab et al., 2013; Duval et al., 2014; Ferizi et al., 2015; Huang et al., 2015) are now starting to verify those findings.
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