APA (7th ed.) Citation

Čajkovskij, P. I., Christensen, F., & Geisler, L. Souvenir de Florence: Sextet for strings, op. 70.

Chicago Style (17th ed.) Citation

Čajkovskij, Pëtr Ilʹič, F. Christensen, and L. Geisler. Souvenir De Florence: Sextet for Strings, Op. 70.

MLA (9th ed.) Citation

Čajkovskij, Pëtr Ilʹič, et al. Souvenir De Florence: Sextet for Strings, Op. 70.