Citazione APA

Howe, J., Tolkien, C., Tolkien, J. R. R., & Sibley, B. (1994). The map of Tolkien's Middle-Earth. HarperCollins.

Stile di citazione Chicago

Howe, John, Christopher Tolkien, J. R. R. Tolkien, e Brian Sibley. The Map of Tolkien's Middle-Earth. London: HarperCollins, 1994.

Citazione MLA

Howe, John, et al. The Map of Tolkien's Middle-Earth. HarperCollins, 1994.