1. Ein Mittel zur Verhutung der Konzeption;Richter;Dtsch. Med. Wochenschr.,1909
2. An intrauterine contraceptive method;Graefenberg,1930
3. A study of intrauterine contraception: development of a plastic loop;Lippes,1962
4. Suppression of fertility by intrauterine copper and zinc in rabbits: A new approach to intrauterine contraception;Zipper;Am. J. Obstet. Gynecol.,1969
5. Intrauterine administration of progesterone by a slow release device;Scommegna;Fertil. Steril.,1970