Besides the following books, web searches for museum displays were often useful, but too numerous to list here.
• Cambridge Encyclopedia of Archaeology: Andrew Sherratt, editor.
• Glossary of the Construction, Decoration and Use of Arms and Armor: George Cameron Stone. This is a fascinating and comprehensive work, though annoyingly lacking in some of the more mundane details such as weights.
• History and Conquests of Ancient Rome: Nigel Rodgers. This is an incredible selection of a wide array of topics regarding the history of Rome. Each topic generally takes two or four pages to describe, which provides a breadth of coverage; the format provides a surprising depth of detail as well. It is focused on the military aspects of Rome.
• Oxford Illustrated History of Medieval Europe: George Holmes, editor.
• Treasury of the Gun: Harold L. Peterson.