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:Haplotype definitions were adapted from the Pharmacogenomics Knowledge Base (PharmGKB) [1], while phenotype translations and clinical guidelines were taken from the Clinical Pharmacogenomics Implementation consortium (CPIC) [2], the Dutch Pharmacogenomics Working Group [3] or the American College of Rheumatology [4].
Category: