1. Anonymous. Epidemiology. Oxford dictionaries online. Oxford: Oxford University Press; 2012.
2. Anonymous. Disease. Oxford dictionaries online. Oxford: Oxford University Press; 2012.
3. Merrill RM. Introduction to epidemiology. 5th ed. Sudbury: Jones and Bartlett Publishers; 2010.
4. Posada de la Paz M, Villaverde-Hueso A, Alonso V, Janos S, Zurriaga O, Pollan M, et al. Rare diseases epidemiology research. In: Posada de la Paz M, Groft SC, editors. Rare diseases epidemiology. Advances in experimental medicine and biology, vol. 686. Dordrecht: Springer Science+Business Media B.V.; 2010. p. 17–39.
5. Groft SC, Brooks PJ, Demory M, Eckstein DJ, Eddy M, Ferguson J, et al. Chiari malformation type 1. Bethesda: Office of Rare Diseases Research, National Institutes of Health; 2012. Available from:
http://rarediseases.info.nih.gov/GARD/Condition/9230/Chiari_malformation_type_1.aspx
.