Isometries of L_p(X;L_q) and Equimeasurability Alexander Koldobskia® Indiana University Mathematics Journal 1991 text pdf 10.1512/iumj.1991.40.40031 10.1512/iumj.1991.40.40031 en Indiana Univ. Math. J. 40 (1991) 677 - 705 state-of-the-art mathematics http://iumj.org/access/