lower left on stone: B.S. (underlined); lower left in graphite: Ed. 35; lower center in graphite: _Riders of the Apocalypse; lower right in graphite: Spruance 43-; lower right corner in graphite by unknown hand: 20-; upper left corner verso in graphite by unknown hand: J-B; lower right verso in graphite by unknown hand: 4276
Reba and Dave Williams, Greenwich, CT; purchased 2008 by NGA
- Fine, Ruth and Robert F. Looney. The Prints of Benton Murdoch Spruance. Philadelphia: University of Philadelphia Press, 1986.