Keweloh, H.W.: 1985 Theiss Stuttgart, hardcover 172 pages, with photos. History of professionel woodrafting on German rivers, with photos. ISBN 3806204268 In very good condition. German language
Kruse, J: 2009 Niemeyer Germany, hardcover 159 pages, with many photos and information of individual ships. ISBN 9783827190932 In very good condition