1. Block, R. J., Jervis, G. A., Bolling, D. & Webb, M. (1940) Journal of Biological Chemistry, 134, 567.
2. Brown, A. C., Belser, R. B., Crounse, R. G. & Wehr, R. (1970) Journal of Investigative Dermatology, 54, 496.
3. Brown, A. C., Gerdes, R. J. & Johnson, J. (1971) Scanning Electron Microscopy, p. 369. Chicago: I.T.T. Research Institute.
4. Chernosky, M. E. & Owens, D. W. (1966) Archives of Dermatology, 94, 577.
5. Danks, D. M., Stevens, B. J., Campbell, R. E., Gillespie, J. M., Walker-Smith, J., Bloomfield, J. & Turner, B. (1972) Lancet, i, 1100.