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 results are better than those in many European countries, for example 29 % in Germany (Roggendorf et al. 2011), 26 % in France (Guthmann et al. 2012), 20 % in Italy (Esposito et al. 2008), 16 % in Greece (Maltezou et al. 2007), 24 % in Turkey (Torun and Torun 2010), 22 % in Australia (Seale et al. 2010a), and 18 % in China (Seale et al. 2010b).
Category: