edited by Vergilius Ferm
Littlefield, Adam and Co., 1959
Buku Referensi
introduction by David Battie
Crescent Books, 1991
Buku Referensi
Buku Teks
edited by Vergilius Ferm
Philosophical Library, 1945
Buku Referensi
Americana corporation, 1938
Buku Referensi