Malcles, L. N., author
Geneve Librairie E. Droz, 1950
Buku Teks
Daniells, Lorna
University of California Press, 1985
Buku Referensi
Institut superieur de philosophie, 1949-1990
Buku Teks
Holm, Jean
Mansell, 1991
Buku Referensi
Pemberton, John E., author
Pergamon Press, 1969
Buku Teks