A. Blouza et H. Ledret, EXISTENCE AND UNIQUENESS FOR KOITER MODEL FOR SHELLS WITH LITTLE REGULARITY, Comptes rendus de l'Academie des sciences. Serie 1, Mathematique, 319(10), 1994, pp. 1127-1132
We give a simple proof of existence and uniqueness for Koiter's model
for shells whose midsurface can have charts with discontinuous second
derivatives. This improves earlier proofs by Bernadou and Ciarlet, the
n by Bernadou, Ciarlet and Miara, for C3-surfaces.