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:Comparison of novel and annotated introns The GC content of both the novel and annotated introns sets was determined using the ‘geecee’ function within the European Molecular Biology Open Software Suite (EMBOSS) (Rice et al. 2000).
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