Selected bibliography:
Seki Humitake: Nihon Budo no Engen: Kashima-Shinryu (1976)
Seki Humitake: Kashima Shinden Bujutsu (2009)
Film material:
Seki Humitake: Nihon Budo no Engen: Kashima-Shinryu (1999). A set of eleven videotapes about Kashima-Shinryu techniques, principles and history (Gaisei International of Japan; including kenjutsu, jujutsu, battojutsu, naginatajutsu, sojutsu, jojutsu, bojutsu & shurikenjutsu).
Websites:
Articles:
Dr. Friday on Koryu legitimacy.
http://www.koryu.com/library/kfriday1.html
http://www.koryu.com/library/kfriday1.html
Prof. Bodiford on Kashima-Shinryu and Maniwa Nenryu. http://www.swordforum.com/forums/showthread.php?104799-Kashima-Shin-Ryu-and-Maniwa-Nen-Ryu&p=1144802#post1144802