Approximately 15 reference and research books. Some to include- "Master French Gunsmith Design" by Stephen Grancrsay (the books are 1 of 1000 and consecutively numbered 250 and 251), "Winchester Slide-Action Rifles" Volumes I & II by Ned Schwing, "Swords of Imperial Japan 1868-1945 Cyclopedia Edition" by Jim Dawson, and "Standard Catalog of Smith & Wesson 3rd Edition" by Jim Supica & Richard Nahas.