Rocker, Rudolf
Freedom Press, 1937
Buku Teks
Mclachlan, Noel
Penguin Book, 1989
Buku Teks
Storry, Richard, 1913-1982, author
Greenwood Press,, 1957
Buku Teks
Francis, John de, author
Princeton University Press , 1950
Buku Teks
edited by Philip Warren Thayer
Johns Hopkins Press, 1956
Buku Teks