- Updating prognosis and therapeutic effect evaluation in cirrhosis with Cox's multiple regression model for time-dependent variables. Christensen, E., Schlichting, P., Andersen, P.K., Fauerholdt, L., Schou, G., Pedersen, B.V., Juhl, E., Poulsen, H., Tygstrup, N. Scand. J. Gastroenterol. (1986)