Thomas, Henry, author
Blakiston, 1946
Buku Teks
edited by Dagobert D. Runes
Littlefield, Adams & Co., 1959
Buku Referensi
Edited by Dagobert D. Runes
Philosophical Library, 1947
Buku Teks
Vreede, Frans, author
Oxford University Press, 1953
Buku Teks
Christensen, Kit R., author
McGraw-Hill, 2002
Buku Teks