Cita APA (7th ed.)
Johnson, R. R. (1976). Elementary statistics (2nd ed.). Duxbury.
Cita Chicago (17th ed.)
Johnson, Robert R. Elementary Statistics. 2nd ed. Massachusetts: Duxbury, 1976.
Cita MLA (9th ed.)
Johnson, Robert R. Elementary Statistics. 2nd ed. Duxbury, 1976.
Atenció: Aquestes cites poden no estar 100% correctes.