Mézes, Lili, Tibor Bíró, János Tamás, and Mihály Petis. 2007. “Heat Treatment and Microbial Digestion of Poulty Feather for Biogas Production”. Acta Agraria Debreceniensis, no. 27 (November): 215-19. https://doi.org/10.34101/actaagrar/27/3128.