Adam, Everett E.
Prentice Hall International, 1992
Buku Teks
McClain, John O.
Prentice-Hall, 1992
Buku Teks
Offord, R. H.
Business Publication , 1967
Buku Teks
Meredith, Jack R.
John Wiley & Sons, 1987
Buku Teks
Meredith, Jack R.
John Wiley & Sons, 1984
Buku Teks