Cita APA (7th ed.)

Tolkien, J. R. R., Carpenter, H., & Tolkien, C. (1981). Letters of J.R.R. Tolkien: A selection. Allen & Unwin.

Cita Chicago (17th ed.)

Tolkien, J. R. R., Humphrey Carpenter, i Christopher Tolkien. Letters of J.R.R. Tolkien: A Selection. London ; Boston: Allen & Unwin, 1981.

Cita MLA (8th ed.)

Tolkien, J. R. R., et al. Letters of J.R.R. Tolkien: A Selection. Allen & Unwin, 1981.