KHAREL, H. L.; SHARMA, R. K.; KANDEL, T. P. Water Hardness Removal Using Wheat Straw and Rice Husk Ash Properties. Nepal Journal of Science and Technology, [S. l.], v. 17, n. 1, p. 11–16, 2016. DOI: 10.3126/njst.v17i1.25057. Disponível em: https://www.nepjol.info/index.php/NJST/article/view/25057. Acesso em: 5 may. 2024.