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:Cerebral saturation in the earlier study (mean6standard deviation: 58%613% ) [37] compares well with both the first (56%610%) and the second (62%66%) layer values, as well as the homogenous values (64%68%) reported here.
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