Jiu Jitsu Complete by Kiyose Nakae

Jiu Jitsu Complete was written to fill the definite need for a more practical, a more complete and more authoritative course on the subject than has heretofore appeared.
Jiu Jitsu depends not on brute strength but on psychology, knowledge of anatomy, and skill that comes from practice in making certain movements with your body.
Practice is essential. However a few simple tricks are enough to put mastery in the hands of the average person who must defend himself against an assailant who has superior strength or who may be armed.
From the Introduction