The General Problem of the Transformation of the Equations of Dynamics Don AufenkampAndre Lichnerowicz Indiana University Mathematics Journal 1952 text pdf 10.1512/iumj.1952.1.51014 10.1512/iumj.1952.1.51014 en Indiana Univ. Math. J. 1 (1952) 499 - 520 state-of-the-art mathematics http://iumj.org/access/