Richard M.Nixon-The Watergate Tapes/Transcripts
http://www.lib.berkeley.edu/MRC/watergate.html

The LBJ,Bobby Baker Scandal
http://educationforum.ipbhost.com/index.php?showtopic=14966

June 17,2002
Tape 342-The 18.5 Minute Gap
http://usgovinfo.about.com/library/weekly/aa081301a.htm

May 8,2003- Tape Gap Still A Mystery
http://www.cbsnews.com/stories/2003/07/27/politics/main565298.shtml

From washingtonpost.com:

Discrediting Kennedy Nixon and John D. Ehrlichman Oct. 8, 1971 John Ehrlichman, the president's chief domestic adviser, tells Nixon that he hopes to receive information on the assassination of South Vietnamese president Ngo Dinh Diem in 1963.