1. Pohlhausen, E., ZAMM 1 (1921) 115.
2. Hayday, A. A., D. A. Bowlus and R. A. McGraw, J. of Heat Transfer, Trans. ASME, Series C, 89, No. 2 (1967) 244.
3. Smith, A. M. O. and D. W. Clutter, A.I.A.A. Journal 1, No. 9 (1963) 2062.
4. Keller, H. B., A New Difference Scheme for Parabolic Problems, Numerical Solution of Partial Differential Equations, Edited by J. Bramble, Academic Press, New York, 1970.
5. Bellman, R. and R. E. Kalaba, Quasilinearization and Nonlinear Boundary Value Problems, American Elsevier, New York, 1965.