APA (7th ed.) Citation

Verdi, G., Piave, F. M., Martin, R., & Martin, T. (1957). Rigoletto: Opera in four acts. G. Schirmer.

Chicago Style (17th ed.) Citation

Verdi, Giuseppe, Francesco Maria Piave, Ruth Martin, and Thomas Martin. Rigoletto: Opera in Four Acts. New York: G. Schirmer, 1957.

MLA (9th ed.) Citation

Verdi, Giuseppe, et al. Rigoletto: Opera in Four Acts. G. Schirmer, 1957.