1. Anderson, B. D. O. and Moore, J. B. (1979). Optimal filtering, Prentice-Hall, Inc. Englewood Cliffs, NJ.
2. Boncelet, C. G. jun. and Dickinson, B. W. (1984). A variant of Huber robust regression, SIAM J. Sci. Stat. Comput. 5: 720-734.
3. Cipra, T. and Romera, R. (1991). Robust Kalman filter and its application in time series analysis, Kybernetika 27: 481-494.
4. Fahrmeir, L. and Künstler R. (1999). Penalized Likelihood Smoothing in Robust State Space Models Metrika 49:173-191.
5. Fox, A. J. (1972). Outliers in Time Series, Journal of the Royal Statistical Society, Series B 43: 350-363.