Raghunathan K, Layton JB, Ohnuma T, Shaw AD. Observational research using propensity scores. Adv Chronic Kidney Dis. 2016 Nov;23(6):367-72. doi: 10.1053/j.ackd.2016.11.010
Brotons C, Rivero E, Perich RM. Hypercholesterolemia in childhood and adolescence. Fmc - Formacion Medica. 1994;4:231-7.