1. W. B. Hanson and R. J. Richards, CEL-NBS Lab, Note 56–1 (1956).
2. R. C. Martinelli and D. B. Nelson, Trans. ASME, Vol. 70, p. 695 (1948).
3. R. W. Lockhart and R. C. Martinelli, Cham. Eng. Progr, Vol 45, No. 1, p. 39 (1949).
4. R. B. Jacobs, NBS Circular 596 (1958).