Heickendorff, L. et al. 1991. Serum aminoterminal propeptide of type III procollagen in systemic sclerosis. A follow-up--investigations in subclasses and during therapy. Acta Dermato-Venereologica. 71, 3 (Jan. 1991), 185–188. DOI:https://doi.org/10.2340/0001555571185188.