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:This prediction has been supported in comparative studies on primates (Short 1979; Harcourt et al. 1981; Harvey and Harcourt 1984; Kappeler 1997a) and many other taxa (review, e.g., in Møller and Briskie 1995).
Category: