Mortrovski, Angel, Nedelcho Nedelchev, and Stoil Kardzhov. “ACTUAL INFECTIOUS DISEASES IN BULGARIAN PIG INDUSTRY”. Archives of Veterinary Medicine 2, no. 2 (December 28, 2009): 3–16. Accessed May 2, 2024. https://niv.ns.ac.rs/e-avm/index.php/e-avm/article/view/214.