1. Catjlfield, J. B., and J. F. Wilgram: J. invest. Derm. 39, 307 (1962).
2. Danbolt, N., and R. Closs: Acta derm.-venerol. (Stockh.) 23, 127 (1942).
3. Degos, R.: Dermatologie, p. 423, 446. Paris, Flammarion 1958.
4. Delacretaz, J., and R. M. Loretan: Proceedings of the XIth International Congress on Dermatology, 1957. Acta derm.-venereol. (Stockh.) 3, 659 (1960).
5. Frost, P., and E. J. van Scott: Arch. Derm. 94, 113 (1966).