A very hard to find to find pristine copy of John Scott Slough's 'An Oshigata Book of Modern Japanese Swordsmiths, 1868–1945'. This is a very useful reference and used by many as a useful guide and oshigata comparison text.
This is a 1st edition: Slough, John Scott. An Oshigata Book of Modern Japanese Swordsmiths, 1868–1945. Rivanna River Company, 2001. White softcover.
Be quick as this very useful book will not hang around!