SANTOSO, A.; SUMARI, S.; ASRORI, M.; NI’MAH, I. Concentration Effect of MgO/K2O Catalyst on Transesterification of Castor Seed (Ricinus communis) Oil. Stannum : Jurnal Sains dan Terapan Kimia, v. 6, n. 2, p. 96-103, 31 out. 2024.