APA (7th ed.) Citation

Blake, W., & Keynes, G. S. (1968). The letters of William Blake. Harvard University Press.

Chicago Style (17th ed.) Citation

Blake, William, and Geoffrey Sir Keynes. The Letters of William Blake. Cambridge, Mass: Harvard University Press, 1968.

MLA (9th ed.) Citation

Blake, William, and Geoffrey Sir Keynes. The Letters of William Blake. Harvard University Press, 1968.