APA (7th ed.) Citation

Backes, M., Dölling, R., & Garvie, F. (1969). Art of the Dark Ages. Harry N. Abrams.

Chicago Style (17th ed.) Citation

Backes, Magnus, Regine Dölling, and Francisca Garvie. Art of the Dark Ages. New York: Harry N. Abrams, 1969.

MLA (9th ed.) Citation

Backes, Magnus, et al. Art of the Dark Ages. Harry N. Abrams, 1969.