Brinton, Crane, 1898-1968
Prentice-Hall, 1955
Buku Teks SO
Cambridge University Press, 2015
Buku Teks SO
Smith, Preserved
Cambridge University Press, 2014
eBooks
Hewlett, Richard G.
Pennsylvania State University Press, 1962
Buku Referensi
Murray, David
Routledge/Thoemmes Press, 1996
Buku Referensi