Jonathan's book, "Thorneycroft to SA80":
https://www.headstamppublishing.com/bullpup-rifle-book

"Clockwork Basilisk: The Early Revolvers of Elisha Collier":
https://www.headstamppublishing.com/collier-book

"Who Invented the Wheelgun?":
https://www.headstamppublishing.com/purchase/p/wheelgun

Armax Journal:
https://www.armaxjournal.org

Jonathan's flintlock revolver article:
https://www.tandfonline.com/eprint/A5R2QAF3HEVSMFJXDVZ6/full?target=10.1080/17416124.2024.2442212

Jonathan's Dafte revolver article is not currently available online, unfortunately.