Imbedding of Compact, Differentiable Transformation Groups in Orthogonal Representations Richard Palais Indiana University Mathematics Journal 1957 text pdf 10.1512/iumj.1957.6.56037 10.1512/iumj.1957.6.56037 en Indiana Univ. Math. J. 6 (1957) 673 - 678 state-of-the-art mathematics http://iumj.org/access/