Albright, Madeleine, author
Harper Perenial, 2008
Buku Teks
Herrick, Christopher, author
Longman, 2003
Buku Teks
Page, Benjamin I., author
University of Chicago Press, 2006
Buku Teks
Martin, Dick, author
American Management Association, 2007
eBooks
Oliphant, Thomas
Thomas Dunne Books, 2007
Buku Teks