Smith, K. J. (1987). The nature of mathematics (5th ed.). Brooks/Cole Pub. Co..
Cita Chicago (17th ed.)Smith, Karl J. The Nature of Mathematics. 5th ed. Monterey, Calif.: Brooks/Cole Pub. Co., 1987.
Cita MLA (9th ed.)Smith, Karl J. The Nature of Mathematics. 5th ed. Brooks/Cole Pub. Co., 1987.
Atenció: Aquestes cites poden no estar 100% correctes.