Henderson, David R.
The joy of freedom : an economist's odyssey
Prentice-Hall, 2002
 Buku Teks
Bryan Lo`s
Wealth life : the easy lifestyle to achieve happiness, wealth and financial freedom
Awesome Books Publishing SDN BHN, 2002
 Buku Teks SO
Bryan Lo`s
Wealth life : the easy lifestyle to achieve happiness, wealth and financial freedom
Awesome Books Publishing SDN BHN, 2002
 Buku Teks SO
Guyer, Paul
Kant on freedom, Law and happiness
Cambridge University Press, 2000
 Buku Teks
Malkani, Vikas
All you wanted to know about happiness/ Vikas Malkani
Gramedia, 2004
 Buku Teks