Amedeo.com, the online Medical Literature Guide, has recently made available the SARS reference -- a "comprehensive and up-to-date overview of severe acute respiratory syndrome" edited by Christian Drosten and Wolfgang Preiser. Offered free of charge to any user, the SARS reference will be updated monthly for the duration of the epidemic. Content includes SARS virology, epidemiology, treatment, a timeline, and a number of other timely and important topics. Users may view chapters individually within their browser, or download the entire publication. Also available in Spanish and Chinese.