Adelard, of Bath, approximately 1090-approximately 1160., Ronca, Italo., Mantas España, Pedro. et Abeele, Baudouin van den., Adelard of Bath, conversations with his nephew : On the same and the different, Questions on natural science, and On birds, Cambridge University Press, (ISBN0-521-39471-6, 978-0-521-39471-0 et 978-0-521-39775-9, OCLC40647111, lire en ligne)
Lewis, Michael John, et Portable Antiquities Scheme (Great Britain),, Inscribed vervels : a corpus and discussion of late medieval and Renaissance hawking rings found in Britain (ISBN978-1-4073-1678-9 et 1-4073-1678-8, OCLC1105151659, lire en ligne)
