1. W. Flügge, Stresses in Shells, 2nd ed. ( Berlin: Springer-Verlag, 1973 ), pp. 100 - 102.
2. V. V. Novozhilov, Thin Shell Theory [translated from 2nd Russian ed. by P. G. Lowe (Groningen, The Netherlands: Noordhoff, 1964), pp. 105-107].
3. P. L. Gould, A. Cataloglu, G. Dhatt, A Chattopadhyay, and R. E. Clark, “Stress Analysis of the Human Heart Valve,” Journal of Computers and Structures, 3, 1973, pp. 377 - 384.
4. S. Timoshenko and S. Woinowsky-Krieger, Theory of Plates and Shells, 2nd ed. ( New York: McGraw-Hill, 1959 ), pp. 449 - 450.
5. Novozhilov, Thin Shell Theory, pp. 117-119.