Emilson, A, et al. “Quantitative and 3 Dimensional Analysis of Langerhans’ Cells Following Occlusion With Patch Tests Using Confocal Laser Scanning Microscopy”. Acta Dermato-Venereologica, vol. 73, no. 5, Oct. 1993, pp. 323-9, doi:10.2340/0001555573323329.