Marcucci, Luisa, author
Studio Books , 1960
Buku Referensi
Wolf, Martin L., author
Philosophical Library, 1958
Buku Referensi
Smith, Bernard, author
Oxford University Press, 1965
Buku Teks
Myers, Bernard S., author
Oxford University Press, 956.
Buku Teks
Cohn, William
Phaidon Press, 1948
Buku Teks