History: The Disputed Origins of the Butterfly Knife

The history of the balisong knife

The History and Origins of the Butterfly Knife – Squid Industries

Answering the Question, Are Butterfly Knives Illegal? - Vander Law

How to use a butterfly knife by Grommet's Knife and Carry - All about butterfly knives by Grommet's Knife and Carry - Learn how to hold and use a butterfly knife

The History of The Balisong Knife – Knife Pivot Lube

At Auction: Stainless Butterfly Knife w/ Ebony Handle Scales

​Interesting Facts About Custom Survival Knives You May Have Not Known - EKnives LLC

A Social and Visual History of the Hudiedao (Butterfly Sword) in the Southern Chinese Martial Arts. – Kung Fu Tea

The Debated Origins of the Balisong Butterfly Knife — KOLLECTIVE HUSTLE