J. R. Shoenfield. The problem of predicativity. Essays on the foundations of mathematics, dedicated to A. A. Fraenkel on his seventieth anniversary, edited by Y. Bar-Hillel, E. I. J. Poznanski, M. O. Rabin, and A. Robinson for The Hebrew University of Jerusalem, Magnes Press, Jerusalem1961, and North-Holland Publishing Company, Amsterdam 1962, pp. 132–139.