Perrin, Towers, author
Irwin , 1997
Buku Referensi
edited by Christopher G. Reddick, Jerrell D. Coggburn
CRC Press, 2008
Buku Referensi
Martocchio, Joseph J., author
McGraw-Hill/Irwin, 2014
Buku Teks
edited by Jerry S. Rosenbloom
Dow Jones-Irwin, 1984
Buku Referensi
Dow Jones-Irwin, 1984
Buku Teks