Madeleine L'Engle (2017). “The Crosswicks Journals: A Circle of Quiet, The Summer of the Great-Grandmother, The Irrational Season, and Two-Part Invention”, p.123, Open Road Media
Madeleine L'Engle, Library of Congress (1984). “Dare to be Creative!: A Lecture Presented at the Library of Congress, November 16, 1983”, Washington : Library of Congress