APA (7th ed.) Citation

Mahler, G., & Blaukopf, H. (1987). Mahler's unknown letters. Northeastern University Press.

Chicago Style (17th ed.) Citation

Mahler, Gustav, and Herta Blaukopf. Mahler's Unknown Letters. Boston: Northeastern University Press, 1987.

MLA (9th ed.) Citation

Mahler, Gustav, and Herta Blaukopf. Mahler's Unknown Letters. Northeastern University Press, 1987.