APA

Dudley U., . (1969). Elementary number theory. New York: W.H. Freeman & Co.

Chicago

Dudley Underwood, . 1969. Elementary number theory. New York: W.H. Freeman & Co.

Harvard

Dudley U., . (1969). Elementary number theory. New York: W.H. Freeman & Co.

MLA

Dudley Underwood, . Elementary number theory. New York: W.H. Freeman & Co. 1969.