Brown, Bethel
John Wiley & Sons, 1958
Buku Teks
Himelfarb, Alexander
McGraw-Hill Ryerson, 1979
Buku Teks
Robert Maynard Hutchins, editor in chief
Encyclopaedia Britannica, Inc., 1952
Buku Referensi
Mitsch, William J., author
John Wiley, 2007
Buku Teks
Schwartz, Robert, 1940-, author
Wiley Blackwell, 2015
Buku Teks