1. Maldia, G., and Holland, J. F., Cancer Chemotherap. Rep., 16, 491 (1962).
2. Mason, E. E., Chin, T., Li, Y. W., and Zifferen, S. E., Cancer Res., 20, 1474 (1960).
3. Falkson, G., and Schulz, E. J., Brit. J. Derm., 72, 296 (1960).
4. Falkson, G., and Schulz, E. J., Brit. J. Derm., 74, 229 (1962).
5. Falkson, G., Sandison, A. G., Jacobs, E. L., and Fichardt, T., S. Afr. Med. J., 37, 712 (1963).