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:Our observations concur with previous studies in C. elegans and rodents, which led the authors to conclude that events early in life might dictate life span (Ben-Zvi et al., 2009; Dillin et al., 2002b; Sun et al., 2009).
Category: