Biographical dictionary of twentieth-century philosophers
edited by Stuart Brown, Diane Collinson, Robert Wilkinson
Roudledge, 1996
 Buku Referensi
Gilbert, Martin
A history of the twentieth century,volume one:1900-1933
Avon books, 1997
 Buku Teks
White, Morton G.
The age of analysis; twentieth century philosophers, selected, with an introd. and interpretive commentary
Books for Libraries Press, [1970, c1955]
 Buku Teks SO
Chronology of twentieth-century history : business and commerce, volume one
edited by Frank N. Magill
Fitzroy Dearborn, 1996
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Sappho
100 (One hundred> lyrics by
London Chatto 1910
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