Michelson, William, author
Addison-Wesley, 1970
Buku Teks
Zand, Dale E., author
McGraw-Hill, 1981
Buku Teks
Cannell, Fenella
Ateneo de Manila University Press, 1999
Buku Teks
Baldridge, J. Victor, author
John Wiley & Sons, 1980
Buku Teks
Henslin, James M., author
Erlangga, 2007
Buku Teks