APA (7e ed.) Bronvermelding

Amthor, T. K., Barrett, K., McBride, A., Ney-Grimm, J., Forton, G., & Tolkien, J. R. R. (1988). A spy in Isengard. Berkley Pub. Group.

Chicago (17e ed.) Bronvermelding

Amthor, Terry K., Kevin Barrett, Angus McBride, Jessica Ney-Grimm, Gerald Forton, en J. R. R. Tolkien. A Spy in Isengard. New York: Berkley Pub. Group, 1988.

MLA (8e ed.) Bronvermelding

Amthor, Terry K., et al. A Spy in Isengard. Berkley Pub. Group, 1988.