I. N. S. Miwada, I. N. S. Sutama, I. K. Sukada, and L. Doloksaribu, “Fortification of goat milk with purple sweet potato (Ipomea batatas l.) extract and its effects on functional cheese”, Int. J. of Life Sci., vol. 3, no. 2, pp. 8–13, Jul. 2019.