Herviyanti -, Maulana A, Pasetyo TB, Omily T, Ryswaldi R. Application of Sub-bituminous Coal Activated with Urea to Improve Chemical Properties of Ultisols and Palm Oil’s Growth (Elaeis Guineensis Jacq.) In Pulau Punjung, Dharmasraya. Int. J. Adv. Sci. Eng. Inf. Technol. [Internet]. 2021 Apr. 27 [cited 2024 Jul. 22];11(2):791-7. Available from: https://ijaseit.insightsociety.org/index.php/ijaseit/article/view/13536