1. Shaffer, J. G., Am. J. Hyg. 57: 366 (1953).
2. Reeves, R. E., Z. Tropenmed. u. Parasitol. 8: 213 (1957).
3. McQuilkin, W. T., J. Natl. Cancer Inst. 19: 885 (1957).
4. Med. Div. Rept. No. 164 U.S. Army Chem. Corps Chem. Center 1948
5. Amberson, W. R., J. Biol. Chem. 181: 405 (1949).