edited by Joseph T. Shipley
Philosophical Library, 1946
Buku Referensi
Lancet, 1926
Buku Referensi
Houghton Miffiln, 1958
Buku Teks
edited by Frank N. Magill
Fitzroy Dearborn Publishers, 1996
Buku Referensi
Strategic Direction Publishers, [date of publication not identified]
Buku Referensi