Sheetz, Michael, author
John Wiley & Sons, 2007
Buku Teks
Chew, Sally
Times Books International, 1995
Buku Teks
Beyfus, Drusilla
Reed International Books, [date of publication not identified]
Buku Teks
Grannell, Craig, author
Springer, 2012
eBooks
Burns, Tom, author
Sage Publications, 2003
Buku Teks