Joan Beaufort, countess of Westmorland, Ownership Confirmed (1426-?) by Will.
Laynesmith, J.L. "'To Please...Dame Cecely that in Latyn hath litell intellect': Books and the Duchess of York," in The Fifteenth Century XV: Writing, Records, and Rhetoric, ed. Linda Clark (Woodbridge, Suffolk; Rochester, NY: Boydell and Brewer, 2017), 37-56.: 48-49, 55
Tuck, Anthony. "Beaufort [married names Ferrers, Neville], Joan, countess of Westmorland (1379?–1440), magnate," in Oxford Dictionary of National Biography (2008).
Edwards, A. S. G. "Northern Magnates and Their Books," Textual Cultures 7, no. 1 (2012): 176-86.