Lewes, George Henry, author
Cambridge University Press, 2013
eBooks
Wolfe, Bertram D.
The Dial Press, 1961
Buku Teks
Klinken, Gerry van, author
KITLV Press, 2003
Buku Teks
Myers, Michele Tolela, author
McGraw-Hill, 1982
Buku Teks
Bormann, Ernest G., author
Harper & Row, 1965
Buku Teks