@article{Allignol2011,
author = {Allignol, A. and Schumacher, M. and Beyersmann, J.},
title= {Empirical transition matrix of multi-state models: The etm package},
year = {2011},
URL = {http://www.jstatsoft.org/v38/i04/},
journal = {Journal of Statistical Software},
volume = {38},
number = {4},
pages = {1--15},
}