Drate, Spencer, author
North Light Books, 1999
Buku Referensi
MacEwan, Grant, author
Western Producer Prairie Books , 1977
Buku Teks
Hawke, Bob
william Heinemann Australia, 1994
Buku Teks
Messing, Bob
Pustaka Binaman Pressindo, 1996
Buku Teks
Bob, Clifford, author
Cambridge University Press, 2005
Buku Teks