Souliw, Charles Georges, author
J. Cape & H. Smith, 1931
Buku Teks
edited by Geoffrey Barraclough
Times Books, 1984
Buku Referensi
Published for Newsweek by Funk & Wagnalls, 1950
Buku Teks
Poeze, Harry A., author
Foris Publications, 1986
Buku Teks
Russell, Bertrand, 1872-1970, author
George Allen and Unwin, 1957
Buku Teks