1. Bucky G. Grenz ray therapy. New York, NY: Macmillan Co; 1929.
2. Hollander MB. Ultrasoft X-rays. An Historical and Critical Review of the World Experience with Grenz Rays and Other X-rays of Long Wave-length. Baltimore, Md: William & Wilkins; 1968.
3. Lindelof B, Liden S, Ros A-M. Effect of grenz rays on Langerhans’ cells in human epidermis. Acta Dermatol Venereol. 1984; 64: 436–438.
4. Lindelof B, Forslind B. Electron microscopic observation of Langerhans’ cells in human epidermis irradiated with grenz rays. Photodermatology. 1985; 2: 367–371.
5. Lindelof B, Liden S, Lagerholm B. The effect of grenz rays on the expression of allergic contact dermatitis in man. Scand J Immunol. 1985; 21: 463– 469.