The Existence and Uniqueness of the Velocity Correlation Derivative in Chandrasekhar's Theory of Turbulence George Backus Indiana University Mathematics Journal 1957 text pdf 10.1512/iumj.1957.6.56009 10.1512/iumj.1957.6.56009 en Indiana Univ. Math. J. 6 (1957) 215 - 233 state-of-the-art mathematics http://iumj.org/access/