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:Although pleural and pericardial effusions are common in SLE and may occur at any time during the disease [5, 6], chylous ascites and chylothorax have rarely been described in patients with SLE [2, 3].
Category: