A. Pérez-Gálvez, M. I. Mínguez-Mosquera, J. Garrido-Fernández, M. M. Lozano-Ruiz, and V. Montero-de-Espinosa, “Correlation between ASTA units-carotenoid concentration in paprika. Prediction of the color stability during storage”, Grasas aceites, vol. 55, no. 3, pp. 213–218, Sep. 2004.