Karakolev, Rumen, Tsvetoslav Koynarski, Reneta Petrova, and Preslava Petrova-Tsenin. 2021. “INFLUENCE OF THE IMMUNOMODULATOR ‘AVIGEN’ ON THE NATURAL RESISTANCE OF ROSS HYBRID BROILER”. TRADITION AND MODERNITY IN VETERINARY MEDICINE 6 (2):95-103. https://www.scij-tmvm.com/index.php/pub/article/view/160.