How many interviews, letters, etc. have been found of the Three Witnesses and their experience seeing the gold plates?
b. The King Follet sermon
The King Follett Discourse given by Joseph Smith is by far his most published sermon—by more than thirty times.
Donald Q. Cannon and Larry E. Dahl, “The King Follett Discourse: Joseph Smith’s Greatest Sermon in Historical Perspective.” BYU Studies 18 (Winter 1978), 179-92.