APA

Guttman B., Hopkins III J., . (1999). Biology. Boston: WCB/McGraw-Hill.

Chicago

Guttman B.S, Hopkins III J.W, . 1999. Biology. Boston: WCB/McGraw-Hill.

Harvard

Guttman B., Hopkins III J., . (1999). Biology. Boston: WCB/McGraw-Hill.

MLA

Guttman B.S, Hopkins III J.W, . Biology. Boston: WCB/McGraw-Hill. 1999.