Foreword by William R. Mead
Tiger Book International, 1995
Buku Referensi
Wiegand, Patrick
Oxford University Press, 1994
Buku Teks
Chalid Latif, author
Pembina Peraga, 1992
Buku Referensi
Encyclopaedia Britannica, 1989
Buku Referensi
Rand McNally, [date of publication not identified]
Buku Referensi