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, edited by Linda Clark, 37-56. Woodbridge, Suffolk; Rochester, NY: Boydell and Brewer, 2017.
Tuck, Anthony. "Beaufort [married names Ferrers, Neville], Joan, countess of Westmorland (1379?–1440), magnate." Oxford Dictionary of National Biography. (2008, January 03).
Edwards, A. S. G. "Northern Magnates and Their Books." Textual Cultures 7, no. 1 (2012): 176-86.