Amthor, T. K., Barrett, K., McBride, A., Ney-Grimm, J., Forton, G., & Tolkien, J. R. R. (1988). A spy in Isengard. Berkley Pub. Group.
Dyfyniad Arddull ChicagoAmthor, Terry K., Kevin Barrett, Angus McBride, Jessica Ney-Grimm, Gerald Forton, and J. R. R. Tolkien. A Spy in Isengard. New York: Berkley Pub. Group, 1988.
Dyfyniad MLAAmthor, Terry K., et al. A Spy in Isengard. Berkley Pub. Group, 1988.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.