1. Oshinovo, T. and Charles, M.E., Vertical Two-Phase Flow, pt. 2: Holdup and Pressure Drop, Can. J. Chem. Eng., 1974, vol. 52, p. 438–448.
2. Ganchev, B.G. and Peresad’ko, V.G., Hydrodynamics and Heat Transfer Processes in Descending Bubble Flows, Inzh.-Fiz. J., 1985, vol. 49, no. 2, pp. 181–189.
3. Gorelik, R.S., Kashinskiy, O.N., and Nakoryakov, V.E., Investigation into Descending Bubbly Flow in a Vertical Pipe, J. Prikl. Mekh. Tekh. Phiz., 1987, no. 1, pp. 69–73.
4. Clark, N.N. and Flemmer, R.L.C., On Vertical Downward Two Phase Flow, Chem. Eng. Sci., 1984, vol. 39, pp. 170–173.
5. Clark, N.N. and Flemmer, R.L.C., Two-Phase Pressure Loss in Terms of Mixing Length Theory, Ind. Eng. Chem. Fund., 1985, vol. 24, pp. 412–423.