APA Edition Citation

Rudoffer, S., & Baker, I. N. (1967). Mathematics observed. Hans Freudenthal.

Chicago Edition Citation

Rudoffer, Stephen, and I N. Baker. Mathematics Observed. London: Hans Freudenthal, 1967.

MLA Edition Citation

Rudoffer, Stephen, and I N. Baker. Mathematics Observed. Hans Freudenthal, 1967.