. New York: Macmillan, 1963.
Handbook for Boys
. New York: Doubleday-Page and Co., 1911
Kubler-Ross, Elisabeth.
Death: The final stage of growth
. Englewood Cliffs, N.J. Prentice-Hall, 1975.
Saotome, Mitsugi.
The Principles of Aikido
. Boston: Shambhala, 1989.
Stevens John.