León-Flández, K. A., Prieto-Castillo, L. and Royo-Bordonada, M. A. (2015) “Traffic light – nutrition labelling: knowledge, perception and use in consumers of Madrid, Spain”, Spanish Journal of Human Nutrition and Dietetics, 19(2), pp. 97–104. doi: 10.14306/renhyd.19.2.150.