Berta, Attila, and Béla Béri. “Examinations Connected With Productive Life in Hungarian Holstein Friesian Populations”. Acta Agraria Debreceniensis, no. 27 (November 15, 2007): 32–39. Accessed May 1, 2024. https://ojs.lib.unideb.hu/actaagrar/article/view/3098.