APA (7th ed.) Citation

Beethoven, L. v., Leppard, R., & Baker, J. Ah! perfido.

Chicago Style (17th ed.) Citation

Beethoven, Ludwig van, Raymond Leppard, and Janet Baker. Ah! Perfido.

MLA (9th ed.) Citation

Beethoven, Ludwig van, et al. Ah! Perfido.

Warning: These citations may not always be 100% accurate.