1. V. I. Romanovskii, The Use of Mathematical Statistics in Experimental Work [in Russian], Moscow, OGIZ (1947).
2. E. S. Ventsel', Probability Theory [in Russian], Moscow, Fizmatgiz (1962).
3. A. Ya. Malis and A. R. Demidov, Machines for Cleaning Grain in Air Flow [in Russian], Moscow, Mashgiz (1962).