Encyclopedia of government and politics; Volume 2
edited by Mary Hawkesworth and Maurice Kogan
Routledge, 1992
 Buku Referensi
International encyclopedia of government and politics; Volume 1
edited by Frank N. Magill
Toppan, 1996
 Buku Referensi
Encyclopedia of government and politics; Volume 1
edited by Mary Hawkesworth and Maurice Kogan
Routledge, 1992
 Buku Referensi
International encyclopedia of linguistics; Volume 2
William Bright, editor-in-chief
Oxford University Press, 1992
 Buku Referensi
International encyclopedia of the social sciences : volume 1 & 2
editor, David L. Sills
Macmillan Co. & The Free Press, 1968
 Buku Referensi