Stevenson, Greg, author
Batsford, 2003
Buku Teks
Hanson, Charles
N.Y. St. Martin's Press , 1982
Buku Teks
McIlroy, John, author
Manchester University Press , 1995
Buku Teks
Cropp, John Anthony David
John Wiley & Sons Ltd., 1970
Buku Teks
Cornish, W.R. (William Rodolph), 1937-, author
Sweet and Maxwell, 2007
Buku Referensi