Gupta, Kamal, author
Tata McGraw-Hill, 1981
Buku Teks
Arens, Alvin A., author
Englewood Cliffs, N.J., Prentice-Hall of Southeast Asia
Buku Teks
Binne, Andrew
Pitman, 1951
Buku Teks
John Wiley & Sons, 2010
eBooks
Ray, J.C., author
Holt, Rinehart and Winston, 1964
Buku Teks