APA

Holub J., Harrison N. & O' Brien J. (2007). Who Was Marco Polo ?. New York: Grosset & Dunlap.

Chicago

Holub Joan, Harrison Nancy and O' Brien John. 2007. Who Was Marco Polo ?. New York: Grosset & Dunlap.

Harvard

Holub J., Harrison N. and O' Brien J. (2007). Who Was Marco Polo ?. New York: Grosset & Dunlap.

MLA

Holub Joan, Harrison Nancy and O' Brien John. Who Was Marco Polo ?. New York: Grosset & Dunlap. 2007.