Horrie, Chris
Simon & Schuster , 1999
Buku Teks
Wurtzel, Alan, author
McGraw-Hill, 1995
Buku Teks
Ward, Peter, author
Focal Press, 2000
Buku Referensi
Self, David, author
Macmilan, 1984
Buku Teks
Zetti, Herbert, author
Wadsworth and Cengage Learning, 2012
Buku Teks