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:The methods used were Maximum Entropy (MAXENT; Phillips et al. 2006, 2008), Genetic Algorithm for Rule Set Production (GARP; Stockwell and Noble 1992) and Mahalanobis distances (Farber and Kadmon 2003).
Category: