Peters, M., & Schaaf, W. L. (1967). Mathematics: A modern approach (2d ed.). Van Nostrand.
Cita Chicago (17th ed.)Peters, Max, i William Leonard Schaaf. Mathematics: A Modern Approach. 2d ed. Princeton, N.J: Van Nostrand, 1967.
Cita MLA (9th ed.)Peters, Max, i William Leonard Schaaf. Mathematics: A Modern Approach. 2d ed. Van Nostrand, 1967.
Atenció: Aquestes cites poden no estar 100% correctes.