8Soldevila M, Calafell F, Helgason A, et al. Bertranpetit J: As- sessing the signatures of selection in PRNP from polymorphism data: results support Kreitman and Di Rienzo's opinion. Trends in genetics, TIG 2005, 21(7):389.
9Hammond K, Leitch H W. The FAO global program for the management of farm animal genetic resources. American Society of Animal Science, 1996.