Citazione APA

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

Stile di citazione Chicago

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

Citazione MLA

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