YU-KUI, Rui. Determination of Contents of Seven Heavy Metals in Chalk. Asian Journal of Chemistry, [S. l.], v. 23, n. 11, p. 5163–5164, 2011. Disponível em: https://asianpubs.org/index.php/ajchem/article/view/11062. Acesso em: 23 jul. 2024.