2020年4月9日閲覧。 ^ Michael K. Jones and Malcolm G. Underwood, The King's Mother: LadyMargaret Beaufort, Countess of Richmond and Derby, (Cambridge University Press
ISBN 9780807875469. https://books.google.com/books?id=6LTqCQAAQBAJ October 26, 2020閲覧。 Seymour, James B., Jr. (2006). “Wells-Barnett, Ida B”. In Finkelman, Paul. Encyclopedia