Finkler, Steven A., author
WB. Saunders, 2000
Buku Teks
Swansburg, Russell C., author
Jones and Bartlett, 1990
Buku Teks
Petit, Thomas A.
John Weatherhill, Inc., 1975
Buku Teks
Macnamara, Jim, author
Prentice Hall Australia, 1996
Buku Referensi
Penner, Susan J., author
Springer, 2017
Buku Teks