Gaya APA

Keeton, W, T., Sumaatmadja, N. (1973). Element Of Biological Science . New York: W.W. Norton and Company Inc..

Gaya MLA

Keeton, William, T.., Sumaatmadja, Nursid. "Element Of Biological Science". New York: W.W. Norton and Company Inc., 1973. Text.