Pechenik, Jan A., author
Longman , 2001
Buku Teks
Kalvelage, Carl, author
Foresman, 1976
Buku Teks
Short, John Rennie, author
Routledge, 1994
Buku Teks
Evera, Stephen van, author
Cornell University Press, 1997
Buku Teks
Woodruff, H. Charles
Howard W. Sams, 1968
Buku Teks