Cita APA (7th ed.)

Billings, W., & Nathan, H. (1961). The continental harmony. Harvard University Press.

Cita Chicago (17th ed.)

Billings, William, i Hans Nathan. The Continental Harmony. Cambridge, Massachusetts: Harvard University Press, 1961.

Cita MLA (9th ed.)

Billings, William, i Hans Nathan. The Continental Harmony. Harvard University Press, 1961.