Nihon budou no engen: Kashima-Shinryû
by Humitake Seki
Hardcover (1976) - in Japanese, hard to get
Kyourin shoin, Tokyo

Legacies of the Sword : The Kashima-Shinryu and Samurai Martial Culture
by Karl F. Friday, Humitake Seki
Hardcover (June 1997) - in English
Univ of Hawaii Press, ISBN: 0824818474

Legacies of the Sword : The Kashima-Shinryu and Samurai Martial Culture
by Karl F. Friday, Humitake Seki
Paperback (July 1997) - in English
Univ of Hawaii Press, ISBN: 0824818792

Various links