Dutta, P. C. and Appelqvist, L.- Åke (1996) “Sterols and sterol oxides in the potato products, and sterols in the vegetable oils used for industrial frying operations”, Grasas y Aceites, 47(1-2), pp. 38–47. doi: 10.3989/gya.1996.v47.i1-2.841.