Sanli, H, et al. “Hyperkeratosis of the Nipple Associated With Chronic Graft Versus Host Disease After Allogeneic Haematopoietic Cell Transplantation”. Acta Dermato-Venereologica, vol. 83, no. 5, Nov. 2003, pp. 385-6, doi:10.1080/00015550310012665.