Rand McNally, editor
Time-Life Books, 1968
Buku Referensi
Macmillan, 1991
Buku Referensi
Gedes & Grosset, 2003
Buku Referensi
University of Technology Sydney
Lovell Johns , 1996
Buku Referensi
C. S. Hammond and Company
C.S. Hammond & Co., [date of publication not identified]
Buku Teks