1. Niosh Criteria for a recommended standard, occupational exposure to coal tar products. U.S. Department of Health, Education and Welfare, Washington, D.C., 1977
2. Treatment of psoriasis: Continued observations on the use of coal tar and ultraviolet light;Goeckerman;Arch Dermatol,1931
3. International Agency for Research on Cancer: Monographs on the evaluation of the ca rcinogenic risk for humans. IARC, Lyon, 1985, vol 35, pp 83-159
4. Mutagenicity of coal tar preparations used in the treatment of psoriasis;Saperstein;Toxicol Lett,1979
5. Mutagenicity of urine from psoriatic patients undergoing treatment with coal tar and ultraviolet light;Wheeler;J Invest Dermatol,1981