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:Surface air temperature data for summer (SSAT) and winter (WSAT), to the nearest 0.1 °C, was collected using the WorldClim database (Hijmans et al., 2005) at every degree of latitude.
Category: