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:…Accession P21334), al-2 (UniProt Accession P37295) and al-3 (UniProt Accession P24322) were used to search the genomic sequence of P. anserina [Espagne et al. 2008), published at http://www.genoscope.cns.fr/externe/ English/Projets/Projet_GA/GA.html (P. anserina sequencing consortium)] for…
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