Letter, 9 January 1973
Letter, 11 January 1973
Letter, 10 September 1973
Letter, 9 November 1973
Letter, 15 January 1973
Letter, 14 September 1973
Letter, 16 February 1972
Letter, 6 March 1972
Letter, 6 March 1972
Letter, 16 May 1972
Letter, 6 July 1972