DiBenedetti DB, Price MA, Andrews EB. Cognitive interviewing in risk minimization survey development: patient and healthcare professional surveys. Expert Rev Clin Pharmacol. 2013;6(4):369-73.
López MV, Rivero E, Serra C, Campo M, Raurich M, Bonfill X. Health survey in health care professionals in Barcelona. Arch Prev Riesgos Laborales. 1998;1(2):55-62.
Rothman KJ, Glass RL, Espinal F, Velez H. Caries-free teeth in the absence of fluoride ion. J Public Health Dent. 1972;32(4):225-8. doi: 10.1111/j.1752-7325.1972.tb03977.x