1. Carol, W. L. L., and Haren, H. B. van (1941). Dermatologica (Basel) 83, 353.
2. Ertl, E. (1943). Mschr. Ohrenheilk, 77, 1c5.
3. Fernandez, A. A., and Monserrat, J. L. E. (1931). Sem. mid. (B. Aires), 38 (2), 1693.
4. Freudenthal, W., Anderson, R. G., and Weber, F. Parkes (1937). Brit. J. Derm., 49, 151.
5. Masson, P. (1924). Lyon chir., 21, 257.