Norwich, John Julius, editor
Oxford University Press, 1990
Buku Referensi
Moore, Frank Ledlie, author
Contemporary books, 1996
Buku Referensi
Heling, Bureau Menno, author
Het Spectrum, 1994
Buku Referensi
edited by Dagobert D. Runes and Harry G. Schrickel
Philosophical Library, 1946
Buku Referensi
editor, John Prest
Oxford University Press, 1993
Buku Referensi