Freund, J. E. (1979). Modern elementary statistics (5th ed.). Prentice-Hall National Book Store.
Cita Chicago (17th ed.)Freund, John E. Modern Elementary Statistics. 5th ed. Englewood Cliffs, N.J., Manila: Prentice-Hall National Book Store, 1979.
Cita MLA (9th ed.)Freund, John E. Modern Elementary Statistics. 5th ed. Prentice-Hall National Book Store, 1979.
Atenció: Aquestes cites poden no estar 100% correctes.