TCG Letter #641 / Carpenter Letter #268

The Letters of J.R.R. Tolkien (1981), p. 354, p. 451 (Carpenter note)

The Letters of J. R. R. Tolkien: Revised and Expanded ed. (HarperCollins, UK), p. 495, p. 632 (Carpenter note)

The J.R.R. Tolkien Companion and Guide - Chronology (2017), p. 661

J.R.R. Tolkien A Descriptive Bibliography, Di1, p. 350; Dii45, p. 361

Sotheby's Catalogue of Valuable Autograph Letters, Literary Manuscripts and Historical Documents 21-22 July 1980, lot 582

Cartas de J.R.R. Tolkien, pp. 504-5, p. 644 (notas de Carpenter)