The Cadmium and lead levels in cow´s milk marketed in the city of Guayaquil, Ecuador. Revista Científica Ciencias Naturales y Ambientales, [S. l.], v. 8, n. 2, p. 6, 2015. DOI: 10.53591/cna.v8i2.221. Disponível em: https://revistas.ug.edu.ec/index.php/cna/article/view/1743. Acesso em: 5 dec. 2025.