Campbell, George L.
Concise compendium of the world's languages
Routledge, 1995
 Buku Referensi
Katzner, Kenneth
The languages of the world
Routledge, 1995
 Buku Referensi
The World's major languages
edited by Bernard Comrie
Oxford University Press, 1987
 Buku Teks SO
The World's major languages
edited by Bernard Comrie
Routledge, 1991
 Buku Referensi
The modernization of languages in Asia
edited by S. Takdir Alisjahbana
Malaysian Society of Asian Studies, 1990
 Buku Teks SO