APA (7th ed.) Citation

Phaidon Press. (1999). Twentieth-century classics. Phaidon Press.

Chicago Style (17th ed.) Citation

Phaidon Press. Twentieth-century Classics. London: Phaidon Press, 1999.

MLA (9th ed.) Citation

Phaidon Press. Twentieth-century Classics. Phaidon Press, 1999.