1. Time factors of erythema and pigmentation produced by ultraviolet rays of different wavelengths;Bachem;J Invest Dermatol,1955
2. Briet R, Kligman A.M: Measurement of erythemal and pigmentary responses to ultraviolet radiation of different spectral qualities, The Biologic Effects of Ultraviolet Radiation. Edited by F Urbach. Oxford, Pergamon Press, pp 267-275
3. Effects of ultraviolet and visible radiation and the production of free radicals in skin;Pathak,1969
4. Pigmentation due to long wave ultraviolet;Henschke;Strahlentherapie,1939
5. Immediate pigmentation in sunlight and artificial light;Monash;Arch Dermatol,1963