Curtis, Gerald L.
Colimbia University Press, 1971
Buku Teks
Curtis, Gerald L.
Columbia University Press, 1971
Buku Teks
Gerald, Curtis F., author
Addison-Wesley, 1999
Buku Teks
World Executive's Digest, 1981
Buku Teks
Hasegawa, Keitaro, author
Kodansha International, 1986
Buku Teks