McArdle , Richard N., and John C. Bouwkamp. “EFFECT OF PECTINASE, CELLULASE AND NUTRIENT ADDITION ON FERMENTATION OF SWEET POTATO MASHES”. Annals of Tropical Research, vol. 8, no. 3, Sept. 1986, pp. 107-14, https://atr.vsu.edu.ph/article/view/694.