A. Faridah, “Comperation of Porang Flour (morphophallus muelleri) Purification Method : Conventional Maceration (gradient ethanol leaching) and Ultrasonic Maceration Method using Response Surface Methodology”, Int. J. Adv. Sci. Eng. Inf. Technol., vol. 6, no. 2, pp. 265–272, Apr. 2016.