1. Ryan TJ. Cutaneous vasculitis. In: Champion RH, Burton JL, Burns DA, Breathnach SM, eds. Textbook of Dermatology, 6th edn. London: Blackwell Science Ltd; 1998. p. 2155–225.
2. Kaplan EL. Rheumatic fever. In: Braunwald E, Fauci AS, Kasper DL, Hauser SL, Longo DL, Jameson JL, eds. Harrison’s Principles of Internal Medicine, 15th edn. New York: McGraw Hill; 2001. p. 1340–3.
3. Erythema nodosum: Etiologic and predictive factors in a defined population