1. Andersen PK (1982) Testing goodness of fit of Cox’s regression and life model. Biometrics 38:67–77
2. Breslow NE (1972) Contribution to the discussion of “regression models and life tables”, by D. R. Cox. J R Stat Soc Ser B 34:216–217
3. Cox DR (1972) Regression models and lifetables. J R Stat Soc Ser B (Methodological) 34(2):187–202
4. Crowder MJ (2001) Classical competing risks. Chapman and Hall, London
5. Dempster AP, Laird NM, Rubin DB (1977) Maximum likelihood from incomplete data via the EM algorithm. J R Stat Soc Ser B 39(1):1–38