Cita APA (7a ed.)

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

Cita Chicago Style (17a ed.)

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

Cita MLA (8a ed.)

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