HERVIYANTI, -; PRASETYO, Teguh Budi; JUNIARTI, -; REZKI, Dewi. Activation Unproductive Coal Powder with Urea to Improve Chemical Properties of Ultisols. International Journal on Advanced Science, Engineering and Information Technology, [S. l.], v. 7, n. 3, p. 957–963, 2017. DOI: 10.18517/ijaseit.7.3.2152. Disponível em: https://ijaseit.insightsociety.org/index.php/ijaseit/article/view/2152. Acesso em: 22 jul. 2024.