Yoshinaga, Eiji, et al. “A Case of Chondrodermatitis Nodularis Chronica Helicis With an Autoantibody to Denatured Type II Collagen”. Acta Dermato-Venereologica, vol. 81, no. 2, Mar. 2001, pp. 137-8, doi:10.1080/00015550152384308.