De Groot G H, Schalm S W, Fick T, Reuvers C B, Boks A L, Terpstra O T
Department of Internal Medicine II, University Hospital Dijkzigt, Rotterdam, The Netherlands.
J Gastroenterol Hepatol. 1989 May-Jun;4(3):283-93. doi: 10.1111/j.1440-1746.1989.tb00836.x.