1. Schwann, T., 1939, Mikroscopische Untersuchungen, p. 174, cited in Greenfield, J. G., Blackwood, W., Meyer, A., McMenemey, W. H., and Norman, R. M., 1960, Neuropathology, Edward Arnold, London.
2. Greenfield, J. G., Blackwood, W., Meyer, A., McMenemey, W. H., and Norman, R. M., 1960, Neuropathology, Edward Arnold, London.
3. Cajal, S. R. y., 1897, Rev. Trimest. Micrograph. Madrid, 2:29.
4. Caspar, D. L. D., Goodenough, D. A., Makowski, L., and Phillips, W. C., 1977, J. Cell Biol. 74:605–628.
5. Goodenough, D. A., Paul, D. L., and Culbert, K. E., 1978, Birth Defects 14:83–97.