Capdevila Bert R, Marsal Mora JR, Pujol Salud J, Anguera Farran R. Prevalence study of iodine deficiency in a 6-year-old school population. An Pediatr (Barc). 2010 May;72(5):331-8. doi: 10.1016/j.anpedi.2009.12.023
Williams VSL, Wakeford ME. The predictive validity of the National Teacher Examinations for performance in teacher education programs. Educ Psychol Meas. 1993;53(2):533-9. doi: 10.1177/0013164493053002023