^Murray, Patrick R. (July 2005). "XX". Medical Microbiology (5th ed.). Philadelphia, Pennsylvania: Elsevier Mosby. pp. XX. ISBN0-323-03303-2. {{cite book}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
^Kumar, Vinay (July 30, 2004). "XX". Robbins and Cotran: Pathologic Basis of Disease (7th ed.). Philadelphia, Pennsylvania: Elsevier Saunders. pp. XX. ISBN0-7216-0187-1. {{cite book}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
^X, X (2001). "XX". In Joel G. Hardman and Lee E. Limbird (ed.). Goodman & Gilman's: The Pharmacological Basis of Therapeutics (10th ed.). New York: McGraw-Hill Companies, Inc. pp. XX. ISBN0-07-135469-7. {{cite book}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
