Sampaio, Carlos Augusto de Paiva, Irenilza de Alencar Nääs, and Douglas D’alessandro Salgado. 2006. “Ammonia, Hydrogen Sulfide, Methane and Carbon Monoxide in Swine Production”. Revista De Ciências Agroveterinárias 5 (2). Lages:156-64. https://revistas.udesc.br/index.php/agroveterinaria/article/view/5391.