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:Furthermore, hypercellular spindle cell areas resembling fibrosarcoma have been described in both SEF and LGFMS (Evans, 1987,
1993; Meis-Kindblom et al., 1995; Antonescu et al., 2001).
Category: