1. Krakower, C., Hoffman, W. A., and Axtmayer, J. H., Puerto Rico J. Pub. Health and Trop. Med., 16, 2, 269 (1940).
2. Abdallah, A., J. Roy. Egypt Med. Assoc., 29, 33 (1946).
3. Neva, F., Amer. J. Trop. Med., 29, 909 (1949).
4. Ferreira, J. M., Rev. Med. Sao Paulo, 38, 181 (1954).
5. Tze-Ying, Tai, Chao-Yueh, Hsu, Hsiao-Chih, Chang, and Yu-K'Un, Liu, Chin. Med. J., 76, 426 (1958).