edited by John Angel, Ian Walden
Blackstone Press, 1997
Buku Referensi
Kennedy, Charles H., author
Artech House, 1996
Buku Teks
Brown, John, 1923-, author
English Language Book Society , 1974
Buku Teks
Brazier, Gil, author
Cavendish, 1996
Buku Teks
Schroeder, Milton R., author
Warren, Gorham & Lamont, 1995
Buku Teks