1. Histopathologic Technic and Practical Histochemistry, p.38. Blakiston;Lillie, R.D.,1954
2. Stuart, R. D., Toshach, S. R., and Patsula, T. M. (1954). Canad. J. publ. Hlth, 45, 73.
3. Trowbridge, M. Jr., and McConkey, R. M. (1944). War Med. (Chic.). 5, 36.