1. McDonald, J. D., Univ. Calif. Pub. Zool. 20: 243 (1922).
2. The Animal Parasites of Man 1916
3. Host-parasite relations between man and his intestinal Protozoa 1927
4. Walker, E. L., Philippine Journ. Sci.. 8: 1 (1913).
5. Dobell, C., Parasit. 18: 283 (1926).