1. Sams WM Jr. Small vessel vasculitis. In: Sams WM Jr, Lynch PJ, eds. Principles and practice of dermatology. New York: Churchill Livingstone, 1990: 523–6
2. Callen JP. Vasculitis. In: Callen JP, Jorizzo JL, Greer KE, et al, eds. Dermatological signs of internal disease. 2d ed. Philadelphia: WB Saunders, 1995: 31–4
3. The American College of Rheumatology 1990 criteria for the classification of hypersensitivity vasculitis