Hose, Charles, 1863-1929
The pagan tribes of Borneo
Oxford University Press, 1993
 Buku Teks
Spencer, Baldwin, 1860-1929
The native tribes of central Australia
Macmillan, 1899
 Buku Teks
Hall, John W.
Twelve doors to Japan
McGraw-Hill, 1965
 Buku Teks
Everyman's encyclopaedia : volume twelve
edited by E. F. Bozman
J. M. Dent & Sons, 1958
 Buku Referensi
Burnison, Gary, 1961-
The twelve absolutes of leadership
McGraw-Hill, 2012
 Buku Teks