APA (7th ed.) Citation

Proch, H., & Liebling, E. (1940). Theme and variations, op.164. Schirmer.

Chicago Style (17th ed.) Citation

Proch, Heinrich, and Estelle Liebling. Theme and Variations, Op.164. New York: Schirmer, 1940.

MLA (9th ed.) Citation

Proch, Heinrich, and Estelle Liebling. Theme and Variations, Op.164. Schirmer, 1940.