Ferguson, Kitty, author
Bantam, 2011
Buku Teks
Fyzee, Murad
New Delhi Tata McGraw-Hill Publishing Company 1991,
Buku Teks
Wendt, Herbert, author
Houghton-Mifflin, 1956
Buku Teks
Embree, Edwin R.
Viking Press , 1944
Buku Teks
Held, Lewis I., 1951-, author
Cambridge University Press, 2014
Buku Teks