Spence, J. T. (1983). Elementary statistics (4th ed.). Prentice Hall.
Lua i Stíl Chicago (17ú heag.)Spence, Janet T. Elementary Statistics. 4th ed. Englewood Cliffs, New Jersey: Prentice Hall, 1983.
Lua MLA (9ú heag.)Spence, Janet T. Elementary Statistics. 4th ed. Prentice Hall, 1983.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.