Plane Strain of a Net Formed by Inextensible Cords R. Rivlin Indiana University Mathematics Journal 1955 text pdf 10.1512/iumj.1955.4.54037 10.1512/iumj.1955.4.54037 en Indiana Univ. Math. J. 4 (1955) 951 - 974 state-of-the-art mathematics http://iumj.org/access/