1. A means of preventing pregnancy;Richter;Dtsch Med Wochenschr,1909
2. Vortrage und Verhandlungen des Arztekursus;Graefenberg,1928
3. Septic spontaneous abortion associated with the Dalkon Shield;Preston,1975
4. The intrauterine device and deaths from spontaneous abortion;Cates;N Engl J Med,1976
5. IUDs: an appropriate contraception for many women;Ory;Popul Rep [B],1982