Katzner, Kenneth, author
The languages of the world
Routledge, 1995
 Buku Referensi
Atlas of the world
Gedes & Grosset, 2003
 Buku Referensi
The celtic world
edited by Miranda J. Green
Routledge , 1997
 Buku Referensi
Perspectives on world
Routledge, 1992
 Buku Teks
A world between
George Braziller, 1999
 Buku Teks