D'Angelo D, Williams L, Morrow B, Cox S, Harris N, Harrison L, Posner SF, Hood JR, Zapata L; Centers for Disease Control and Prevention (CDC).
MMWR Surveill Summ. 2007 Dec 14;56(10):1-35. Erratum in: MMWR Morb Mortal Wkly Rep. 2008 Apr 25;57(16):436.