Popescu, Calin
Wiley, 1995
Buku Referensi
Patrick, Charles
Pearson/Prentice Hall, 2004
Buku Teks
Kerzner, Harold R.
Van Nostrand Reinhold, 1995
Buku Teks
Kerzner, Harold R.
John Wiley & Sons, 2006
Buku Teks
Kerzner, Harold R.
Van Norstrand Reinhold, 1989
Buku Teks