Knuth, Donald E. (1996), «Questions and Answers II», TUGboat17: 355-367.. Reprinted as chapter 32 of Digital Typography, pp. 601–624. See especially p. 364 (p. 620): "And the third source was a copy of Indagationes Mathematicae, the Dutch journal. There's a long fine tradition of quality printing in the Netherlands, and I selected an issue from 1950 or thereabouts, where again I thought that the mathematics was particularly well done."
