Text ( visual ) : unmediated The middle ages / edited by W. F. Bolton. -- Harmondsworth, Middlesex : Penguin , 1993. -- 436 p. ; 20 cm. -- (The Penguin history of literature ; v. 1). -- Includes bibliographical references (p. [401]-421) and index ; Originally published: London : Sphere Books, 1970. -- ISBN 0140177515 ; (BA21015597) ; https://ci.nii.ac.jp/ncid/BA21015597 Author Heading(s): Bolton, W. F. (Whitney French). -- Classification(s): NDC8 : 930.2