APA

Walker H. M., Lev J., . (1969). Elementary statistical methods. New York: Holt, Rinehart and Winston.

Chicago

Walker Helen Mary, Lev Joseph, . 1969. Elementary statistical methods. New York: Holt, Rinehart and Winston.

Harvard

Walker H. M., Lev J., . (1969). Elementary statistical methods. New York: Holt, Rinehart and Winston.

MLA

Walker Helen Mary, Lev Joseph, . Elementary statistical methods. New York: Holt, Rinehart and Winston. 1969.