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:A similar pattern in the response of n-3 and n-6 PUFA to the maternal diet supplemented with salmon oil was reported by other authors (Arbuckle and Innis, 1993; Fritsche et al. 1993; Rooke et al., 2001; Lauridsen and Jensen, 2007).
Category: