Peschen, M, et al. “Modulation of Urokinase-Type and Tissue-Type Plasminogen Activator Occurs at an Early Stage of Progressing Stages of Chronic Venous Insufficiency”. Acta Dermato-Venereologica, vol. 80, no. 3, May 2000, pp. 162-6, doi:10.1080/000155500750042880.