Published January 1981
Published January 1982
Published January 1994
Published June 1996
Published May 1998
Published July 1999
Published December 1999
Published January 2000
Published March 2000
Published July 2000
Published November 2000
Published December 2001
Published May 2002
Published December 2002
Published February 2003
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Published September 2005
Published May 2006
Published September 2006