Page, Andrew C., author
Cambridge University Press, 2014
eBooks
Bennett, Paul, author
McGraw-Hill, 2011
Buku Teks
Bennett, Paul, author
Open University Press, 2003
Buku Teks
Phares, E. Jerry, author
Cole Publishing, 1992
Buku Teks
Sarafino, Edward P., author
John Wiley & Sons, 1994
Buku Teks