1. Bodian, M., and Lawson, D. (1953). Brit. J. Surg., 40, 368.
2. Brain Tumors of Childhood;Cuneo, H.M.; Rand, C.W.,1952
3. Intracranial Tumours;Cushing, H.,1932
4. Herren, R. Y. (1941). Arch. Surg. (Chicago), 42, 758.
5. Posey, L. C. (1942). Arch. Path. (Chicago), 34, 911.