REFERENCES
- Willis, R. A.: Pathology of Tumors. London, Butterworth & Co., 1948.
- Willis, R. A.: Teratomas. In: Atlas of Tumor Pathology. Washington, Armed Forces Institute of Pathology, 1951, Section III, Fascicla 9.
- Nicholson, G. W. DeP.: Studies on Tumor Formation. London, Butterworth & Co., 1950, p. 251.