APA (7th ed.) Citation

Donizetti, G., Bidera, G. E., & Révoil, B. H. (1848). Gemma di Vergy: A tragic opera in two acts = Gemma of Vergy. J. Douglas.

Chicago Style (17th ed.) Citation

Donizetti, Gaetano, Giovanni Emanuele Bidera, and Bénédict Henry Révoil. Gemma Di Vergy: A Tragic Opera in Two Acts = Gemma of Vergy. New York: J. Douglas, 1848.

MLA (8th ed.) Citation

Donizetti, Gaetano, et al. Gemma Di Vergy: A Tragic Opera in Two Acts = Gemma of Vergy. J. Douglas, 1848.