edited by Geoffrey Barraclough
Times Books, 1984
Buku Referensi
McEvery, Colin, author
Facts On File, 1979
Buku Referensi
McNally, Rand, author
Rand McNally & Co, 1957
Buku Referensi
London Chancellor Press 1999,
Buku Referensi
Philips, author
Chancellor Press, 1999
Buku Referensi