Tai, Hue-Tam Ho
Harvard University Press, 1992
Buku Teks
Bianco, Lucien, author
Stanford University Press, 1971
Buku Teks
Flinn, M.W., author
Longman, 1969
Buku Teks
Salvemini, Gaetano
W.W. Norton & Company, 1962
Buku Teks
Gershoy, Leo, author
Appleton Century Crofts, 1938
Buku Teks