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:…other straining characteristics of the disease, such as self-harming behavior, affective dysregulation, and impaired social functioning in the longterm course (BPD; Stiglmayr et al., 2005; Gunderson, 2007; Zanarini et al., 2007; Skodol, 2008; Gunderson, 2011; Livesley, 2012; Dammann et al., 2016).
Category: