K. SUMADA; L. U. WIDODO. Liquid Bio-Silica Fertilizer from Ash Solid Waste of Sugar Industry. Nusantara Science and Technology Proceedings, Malang, Indonesia, p. 224–230, 2019. Disponível em: https://nstproceeding.com/index.php/nuscientech/article/view/104. Acesso em: 30 jul. 2025.