1. Gutmann, Kongreßzbl. inn. Med.67, 516 (1932).
2. Tinel u.Jaquelin, Kongreßzbl. inn. Med.63, 654 (1931).
3. Witts, Kongreßzbl. inn. Med.71, 571 (1933).
4. Laughlin, Kongreßzbl. inn. Med.63, 731 (1931).
5. Barthelheimer, Kongreßzbl. inn. Med.98, 207 (1939).