Wade, Nicholas (31 October 2010), Europe's Plagues Came From China, Study Finds, The New York Times, retrieved 1 November 2010
↑ Nicholas Wade (३१ अक्टोबर २०१०), "Europe’s Plagues Came From China, Study Finds", The New York Times, अभिगमन मिति १ नोभेम्बर २०१०।