| − | Talaro, Kathleen P. and Talaro, Arthur (1999). ''Foundations in Microbiology'' (Columbus, OH: WCB/McGraw-Hill), 3rd ed., p. 10. | + | Talaro, Kathleen P. and Talaro, Arthur (1999). ''Foundations in Microbiology'' (Columbus, OH: WCB/McGraw-Hill), 3rd ed., p. 10. |