Johnson, R. R. (1976). Elementary statistics (2nd ed.). Duxbury.
Lua i Stíl Chicago (17ú heag.)Johnson, Robert R. Elementary Statistics. 2nd ed. Massachusetts: Duxbury, 1976.
Lua MLA (9ú heag.)Johnson, Robert R. Elementary Statistics. 2nd ed. Duxbury, 1976.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.