A Theorem on Spinor-Tensors Joseph Zund Indiana University Mathematics Journal 1966 text pdf 10.1512/iumj.1966.15.15016 10.1512/iumj.1966.15.15016 en Indiana Univ. Math. J. 15 (1966) 221 - 225 state-of-the-art mathematics http://iumj.org/access/