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:The compression of the female thorax in longitudinal direction is a general phenotype in brachypterous lepidopterans with a distinctly enlarged abdomen (Snäll et al. 2007; Wahlberg et al. 2010).
Category: