APA (7th ed.) Citation

Goethe, J. W. v., Auden, W., & Mayer, E. (1995). Letters from Italy. Penguin Books.

Chicago Style (17th ed.) Citation

Goethe, Johann Wolfgang von, W.H Auden, and Elizabeth Mayer. Letters from Italy. London: Penguin Books, 1995.

MLA (9th ed.) Citation

Goethe, Johann Wolfgang von, et al. Letters from Italy. Penguin Books, 1995.