Aritonang, Salam N., et al. “The Effect of Adding ‘Tape Singkong’ (Fermented Cassava) Juice on the Characteristics of Fermented Milk”. Pakistan Journal of Nutrition, vol. 11, no. 4, Mar. 2012, pp. 350–352, https://doi.org/10.3923/pjn.2012.350.352.