A history of cheating in chess (1)
http://www.chessbase.com/newsdetail.asp?newsid=7567

A history of cheating in chess (2)
http://www.chessbase.com/newsdetail.asp?newsid=7575

A history of cheating in chess (3)
http://www.chessbase.com/newsdetail.asp?newsid=7767

A history of cheating in chess (4)
http://www.chessbase.com/newsdetail.asp?newsid=7952