APA-referens (7:e uppl.)

WALKER, H. M. (1969). Elementary statistical methods. Holt, Rinehart and Winston.

Chicago-referens (17:e uppl.)

WALKER, Helen M. Elementary Statistical Methods. New York: Holt, Rinehart and Winston, 1969.

MLA-referens (9:e uppl.)

WALKER, Helen M. Elementary Statistical Methods. Holt, Rinehart and Winston, 1969.