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3. P. van Carey and J. C. Mollendorf, ?Variable viscosity effects in several natural convection flows,? Int. J. Heat Mass Transfer,23, 95 (1980).
4. V. G. Levich, Physicochemical Hydrodynamics [in Russian], Fizmatgiz, Moscow (1959), p. 699.
5. H. Lamb, Hydrodynamics, Cambridge (1932).