APA (7th ed.) Citation

Beethoven, L. v., von Bulow, H., Lebert, S., & Baker, T. (1926). Variations for the piano. G. Schirmer.

Chicago Style (17th ed.) Citation

Beethoven, Ludwig van, Hans von Bulow, Sigmund Lebert, and Theodore Baker. Variations for the Piano. New York: G. Schirmer, 1926.

MLA (9th ed.) Citation

Beethoven, Ludwig van, et al. Variations for the Piano. G. Schirmer, 1926.