Dennis Palumbo is a Kaiden Shihan of Hakkoryu Jujutsu, based in Denver, CO.
Hanshi Palumbo has published three books with Paladin Press:
Secrets Of Hakkoryu Jujutsu: Shodan Tactics
Secret Nidan Techniques Of Hakkoryu Jujutsu
Techniques of Sandan GI: The Essence of Hakkoryu Jujutsu
Hanshi Palumbo blessed my research by giving me a copy of his home-video recordings of advanced students demonstrating every technique of the Shodan, Nidan and Sandan levels. These videos are not available to outsiders, but have been enormously helpful to me. I am extremely grateful to Master Palumbo for extending me this privilege.
In Hanshi Palumbo's jujutsu studio there was a sign on the wall. "If you leave the room without having an injury, one will be provided."