1. R. L. Zenkov, G. P. Grinevich, and V. S. Isaev, Hopper Devices [in Russian], Mashinostroenie, Moscow (1977).
2. A. W. Jenike, Warehousing and Discharge of Granular Materials [in Russian], Mir, Moscow (1968).
3. A. W. Jenike, P. J. Elsey, and R. H. Wooley, “Flow of bulk solids,” Progress Report, Bul. 96, Utah Engineering Experiment Station, University of Utah, Dec. 1958.
4. A. F. Revuzhenko, S. B. Stazhevskii, and E. I. Shemyakin, “Asymmetry of plastic flow in converging symmetric channel,” Fiz.-Tekh. Probl. Razrab. Polezn. Iskop, No. 3 (1977).
5. A. F. Revuzhenko, S. B. Stazhevskii, and E. I. Shemyakin, “Asymmetry of plastic flow in converging axiosymmetric channels,” Dokl. Akad. Nauk SSSR, 246, No. 3 (1979).