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:Corynebacterium glutamicum ATCC 13032 is a nonsporulating and non-pathogenic soil bacterium belonging to the group of high G + C Gram-positive Actinobacteria (Hecht & Causey, 1976; Stackebrandt et al., 1997).
Category: