On the Completeness of Cartan Connections Yeaton Clifton Indiana University Mathematics Journal 1967 text pdf 10.1512/iumj.1967.16.16038 10.1512/iumj.1967.16.16038 en Indiana Univ. Math. J. 16 (1967) 569 - 576 state-of-the-art mathematics http://iumj.org/access/