APA (7th ed.) Citation

Tolkien, J. R. R., & Tolkien, C. (1992). Tree and leaf: Including the poem Mythopoeia. Grafton.

Chicago Style (17th ed.) Citation

Tolkien, J. R. R., and Christopher Tolkien. Tree and Leaf: Including the Poem Mythopoeia. London: Grafton, 1992.

MLA (8th ed.) Citation

Tolkien, J. R. R., and Christopher Tolkien. Tree and Leaf: Including the Poem Mythopoeia. Grafton, 1992.