APA (7th ed.) Citation

Walpole, H., & Toynbee, H. (1903). The letters of Horace Walpole. Clarendon Press.

Chicago Style (17th ed.) Citation

Walpole, Horace, and Helen Toynbee. The Letters of Horace Walpole. Oxford: Clarendon Press, 1903.

MLA (8th ed.) Citation

Walpole, Horace, and Helen Toynbee. The Letters of Horace Walpole. Clarendon Press, 1903.