Aparicio, R., M. Sánchez Navarro, and M. S. Ferreiro. “Definite Influence of the Extraction Methods on the Chemical Composition of Virgin Olive Oil”. Grasas Y Aceites, vol. 42, no. 5, Oct. 1991, pp. 356-62, doi:10.3989/gya.1991.v42.i5.1220.