Kent, Percy Horace
Edward Arnold , 1912.
Buku Teks
Homour, Hugh
London Longmans Green 1957
Buku Teks
Bird, John, 1941-, author
Paul Elek, 1976
Buku Teks
Hulbert, Homer B., author
Yonsei University Press, 1969
Buku Teks
Buck, Pearl Sydenstricker, 1892-1973, author
John Day, 1962
Buku Teks