Here's the quote you seek. Oskar Lange, "On the Economic Theory of Socialism," reprinted in _On the Economic Theory of Socialism_, edited by Benjamin E. Lippincott (U. Minnesota Press, 1938), pp. 57-58: "Both as an expression of recognition for the great service rendered by him and as a memento of the prime importance of sound economic accounting, a statue of Professor Mises ought to occupy an honorable place in the great hall of the Ministry of Socialization or of the Central Planning Board of the socialist state." Bruce Caldwell