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 findings from the experimental studies considered (Von der Behrens et al., 2009; Anderson et al., 2009; Malmierca et al., 2009; Ulanovsky et al., 2004, 2003) vary in
respect to their details but nevertheless appear to reveal a set of common relations between these basic parameters and the SI.
Category: