APA (7th ed.) Citation

Wagner, R., Wagner, M., & Ellis, W. A. (1909). Richard to Minna Wagner: Letters to his first wife. H. Grevel.

Chicago Style (17th ed.) Citation

Wagner, Richard, Minna Wagner, and William Ashton Ellis. Richard to Minna Wagner: Letters to His First Wife. London: H. Grevel, 1909.

MLA (9th ed.) Citation

Wagner, Richard, et al. Richard to Minna Wagner: Letters to His First Wife. H. Grevel, 1909.