APA (7th ed.) Citation

Schumann, C., Schumann, R., & Iwai, Y. (1999). Piano music. HNH Int.

Chicago Style (17th ed.) Citation

Schumann, Clara, Robert Schumann, and Yoshiko Iwai. Piano Music. Unterhaching, Munich, Germany: HNH Int, 1999.

MLA (9th ed.) Citation

Schumann, Clara, et al. Piano Music. HNH Int, 1999.