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:…by other field surveys also showed that Aurelia spp. polyps were primarily located on the undersides of artificial structures in the coastal waters of Japan, the UK, and the Mediterranean Sea (Miyake et al., 2002; Purcell et al., 2009;
Duarte et al., 2012; Malej et al., 2012; Marques et al., 2015).
Category: