Nishi, Kazuo
Kodansha International, 1985
Buku Teks SO
edited by James C. Synder and Anthony J Catanese
McGraw-Hill, 1979
Buku Teks SO
Kawazoe, Noboru
Kokusai Koryu Kikin, 1973
Buku Teks SO
Carver, Norman F.
Shokokusha, 1955
Buku Teks SO
Sadler, A. L.
Charles E. Tuttle, 1962
Buku Teks SO