"Dzhon Vil'gel'movich Peper-Pogan'," in L. I. Shvetsova, et al. (eds.), Rasstrel'nye spiski: Moskva, 1937–1941: “Kommunarka,” Butovo: Kniga pamiati zhertv politicheskikh represii. Moscow: Obshchestvo “Memorial”/Izdatel'stvo “Zven'ia,” 2000, pg. 316. For a full English translation of this material, see: Tim Davenport (trans.), John Wilhelmovich Pepper-Pogány: Arrest and Execution Information: (executed 8 Feb. 1938), Marxists Internet Archive, Retrieved 13 October 2009.