by James J. Nora [and others]
[publisher not identified], [date of publication not identified]
Buku Teks
James J. Nora [and others]
Lea & Febiger , 1993
Buku Teks
Barker, D.J.P., author
Churchil Livingstone, 1976
Buku Teks
edited by L.G. Whitby and Walter Lutz
Churchill Livingstone, 1971
Buku Referensi
Beyers, Marjorie, author
Little, Brown, 1984, 1984
Buku Teks