Yorkshire, UK: Pen & Sword Military, (2018) dj. Hardcover first edition - Revisits the giant pens built during World War II in the ports of Brittany, France, to shelter more than a dozen submarines at one time. Illustrated throughout with over 150 photographs of then and now, in both black and white and full-color. Bibliography, index. Slightly oversized. 175 pp plus final photograph. ISBN: 978-1526705440.