1. Monte Carlo evidence on panel data regressions with AR(1) disturbances and an arbitrary variance on the initial observations;Baltagi;J. Econometrics,1992
2. Böehning, D. (1992). The distribution of the likelihood ratio for mixtures of densities for the one parameter exponential family. XVIth International Biometrics Conference: Proceedings of Contributed Papers, Hamilton, New Zealand, 64.
3. Maximum likelihood from incomplete data via the EM algorithm;Dempster;J. Roy. Statist. Soc. Ser. B,1977