Butler, George D.
McGraw-Hill Book Company, Inc., 1949
Buku Teks
Fitzgerald, Gerald B.
A.S.Barnes and Company, 1948
Buku Teks
Rodden, John, author
[Cambridge University Press;, ], 2012
eBooks
Henry, Nancy, author
Cambridge University Press, 2008
eBooks
Shinn, George
Gregg Division, McGraw-Hill, 1982
Buku Teks