الأسود وطابقين فيبرو صمام تتمحور دليل طاحونة. Wade Hampton Frost, Pioneer Epidemiologist 2004. Dec 16, 2004 Wade Hampton Frost, Pioneer Epidemiologist. 1880-1938 (University of Rochester Press, 2004), the pioneering epidemiologist would hold a cigarette in one hand while lecturing in the classroom, a piece of chalk in the other (almost never writing ...