Burickson, Sherwin
Philosophical Library, 1959
Buku Referensi
ProQuest, 2009
Buku Referensi
Arnason, H. Harvard
Thames & Hudson, 1998
Buku Referensi
edited by G. Goodwin
Cambridge University Press, 1958
Buku Teks
Palmer, Robert Roswell, 1909-2002
McGraw-Hill, 1992
Buku Teks