M. Riccardi, A. Chialà, F. Iannone, V. Grattagliano, M. Covelli, and G. Lapadula, “Treatment of digital ulcers in systemtic sclerosis with endothelin-1 receptor antagonist (bosentan)”, Reumatismo, vol. 59, no. 2, pp. 135–139, Jun. 2007.