1. Statistical Database of the Food and Agriculture Organization of the United Nationshttp://www.fao.org/dad-is/browse-by-country-and-species/en/
2. AIA, Associazione Italiana Allevatori (Italian breeders’ association) web sitehttp://www.aia.it/aia-website/it/home
3. PSR RAS, Programma di Sviluppo Rurale 2007–2013 della Regione Autonoma della Sardegna reg (CE) N 1698/2005 (Rural Development Program of the Regional Government of Sardinia, Cagliari, Italy; in Italian)http://www.regione.sardegna.it/
4. SIAll, Sistema Informativo Allevatori (Breeders’ Informative System) Web Site. SIAll–AIA, Roma, Italyhttp://www.puma-project.it