Symplectic Structures on Integral Manifolds S. Shahshahani Indiana University Mathematics Journal 1974 text pdf 10.1512/iumj.1974.23.23017 10.1512/iumj.1974.23.23017 en Indiana Univ. Math. J. 23 (1974) 209 - 211 state-of-the-art mathematics http://iumj.org/access/