Smaller Reference Sources
General Reference Books – With only Small sections on Locks/Keys
- Classic French Wrought Iron – Twelfth–Nineteenth Century by Raymond Lecoq. Published in 2005. ISBN 10: 039373157X. ISBN 13: 9780393731576.
- Contains chapters on locks, keys, and bolts.
- Chatelaines: Utility to Glorious Extravagance. Written by Genevieve Cummins in 1994. ISBN 10: 1851492062. ISBN 13: 781851492060.
- Contains information and pictures of chatelaines containing keys.
- Specimens of Ancient Furniture with descriptions by Sir Samuel Rush Meyrick. Published in 1836, 1866. Written by Henry Shaw and Samuel Rush Meyrick.
- Pictures of at least one lock/keys from an old church of St. Pitie at Louvain.
- The National Encyclopedia: A Dictionary of Universal Knowledge.
- Contains a section on locks including a plate. Probably volume 8 for the section on locks.
Historical Reference Books – Hardware
- Locks and Builders Hardware – a Hand Book for Architects. Available for free reading at Google Books: +
- Code of Fair Competition for the Lock and Builders Hardware Manufacturing Industry as Submitted on August 29, 1933. Available for free reading at Archive.org +