Implementation of a national registry for patients with primary biliary cholangitis (PBC): the German PBC cohort - Wiegand, J; Günther, R; Naumann, U; Stölzel, U; Berg, C; Bantel, H; Stein, K; Heinzow, H; AE, Kremer; WP, Hofmann; Kautz, A; Beuers, U; Trautwein, C; Franke, A; Piotrowski, K; Berg, T (Zeitschrift für Gastroenterologie, 2020)