APA (7th ed.) Citation

Sor, F., Sor, F., Sor, F., Sor, F., & Sor, F. (1991). Guitar music. Polygram.

Chicago Style (17th ed.) Citation

Sor, Fernando, Fernando Sor, Fernando Sor, Fernando Sor, and Fernando Sor. Guitar Music. Hamburg: Polygram, 1991.

MLA (9th ed.) Citation

Sor, Fernando, et al. Guitar Music. Polygram, 1991.