Sword Books:https://www.pen-and-sword.co.uk/Twentieth-Century-Cop-Hardback/p/57380Also available at Amazon:https://www.amazon.co.uk/Twentieth-Century-Cop-Flying-Detective/dp/1036199517/Waterstones:https://www.waterstones.com/book/twentieth-century-cop/barry-appleton/oliver-crocker/9781036199517Or order through your local bookshop.