Kokushi Ryu Jujutsu Book by Nobuyoshi Higashi

Long before the founding of such arts as karate and aikido; jujutsu was being honed and tested on the battlefield by the Japanese samurai. Its techniques and philosophies make it one of the most effective arts ever devised. To this day it has proven to be nearly unbeatable when tested against other arts. 

Nobuyoshi Higashi is a Japanese American teacher of Tomiki Aikido, karate, and judo, and the founder of Kokushi-ryu jujutsu. He is a 10th dan in jujutsu, 9th dan in judo, 7th dan in aikido, and 7th dan in karate. His style of aikido includes defenses against knives.