Ahmadou Alioum Daniel Commenges MKVPCI: a computer program for Markov models with piecewise constant intensities and covariates. 109-119 2001 64 Computer Methods and Programs in Biomedicine 2 http://dx.doi.org/10.1016/S0169-2607(00)00094-8 db/journals/cmpb/cmpb64.html#AlioumC01