Botahala, L. et al. 2019. Determination of Effectiveness Absorption of The Rice Husk And Hazelnut Shell to Purification Used Cooking Oil. Jurnal Akta Kimia Indonesia (Indonesia Chimica Acta). 12, 1 (May 2019), 19–28. DOI:https://doi.org/10.20956/ica.v12i1.6172.