Langtry, JA, and BL Diffey. “A Double-Blind Study of Ultraviolet Phototherapy in the Prophylaxis of Chilblains”. Acta Dermato-Venereologica 69, no. 4 (July 17, 1989): 320–322. Accessed June 29, 2026. https://medicaljournalssweden.se/actadv/article/view/4677.