Bodnar, George H., author
Prentice Hall International, 1995
Buku Teks
Gelinas, Ulric J., author
South-Western , 2005
Buku Teks
Gelinas, Ulric J., author
South-Western , 2005
Buku Teks
Moscove, Stephen A., author
John Wiley and Sons, 1981
Buku Teks
Moscove, Stephen A., author
John Wiley and Sons, 1997
Buku Teks