Cita APA (7a ed.)

Zyl, A. J. v. (1944). Mathematics at the cross-roads. Maskew Miller.

Cita Chicago Style (17a ed.)

Zyl, Abraham Johann van. Mathematics at the Cross-roads. Cape Town: Maskew Miller, 1944.

Cita MLA (8a ed.)

Zyl, Abraham Johann van. Mathematics at the Cross-roads. Maskew Miller, 1944.