1. Albright, L., Madigan, J. C., Gaston, M. R., Houchens, D. P.: Therapy in an intracerebral murine glioma model, using Bacillus Calmette-Guerin, neuraminidase-treated tumor cells, and 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea. Cancer Res.35, 658?665 (1975)
2. Ames, R. P., Rubin, R. C.: Morphology of virus-like particles persisting in murine ependymoblastoma in vitro. Cancer Res.30, 1142?1148 (1970)
3. Augusti-Tocco, G., Sato, G.: Establishment of functional clonal lines of neurons from mouse neuroblastoma. Proc. Natl. Acad. Sci. U.S.A.64, 311?315 (1969)
4. Ausman, J. L., Shapiro, W. R., Rall, D. P.: Studies on the chemotherapy of experimental brain tumors: Development of an experimental model. Cancer Res.30, 2394?2400 (1970)
5. Bernhard, W., Granboulan, N.: Electron microscopy of the nucleolus in vertebrate cells. In: The nucleus (Dalton, A. J., Haguenau, F., eds.), pp. 81?137, New York: Academic Press 1968