1. Valves in the veins—an historical survey;Franklin;Proc R Soc Med,1927
2. Early accounts of the valves of the veins;Leibowitz;Journal of the History of Medicine,1957
3. Die Entdeckung der Venenklappen;Steudel;Dtsch Med Wochenschr,1955
4. The world of Asklepios—a history of medicine in objects;Ackerknecht,1966
5. Venous valves;Gottlob,1986