BUNNAKKHA, C.; JARUPISITTHORN, C. Extraction of tin from hardhead by oxidation and fusion with sodium hydroxide. Journal of Metals, Materials and Minerals, Bangkok, Thailand, v. 22, n. 1, 2012. DisponĂ­vel em: http://jmmm.material.chula.ac.th/index.php/jmmm/article/view/16. Acesso em: 2 dec. 2021.