Heinrich & Bonifacius Welsch, sons of Peter Welsch, are recorded on the 1798 census of Seelmann in Household No. Sm19.
Heinrich Wilhelm and Bonifacius Welsch and his son are recorded on the 1811 census of Seelmann in Household No. 19 along with a note that Heinrich Wilhelm had relocated to Neu-Kolonie in 1809.
- 1811 Seelmann Census (Household No. 19).
- Mai, Brent Alan. 1798 Census of the German Colonies along the Volga: Economy, Population, and Agriculture (Lincoln, NE: American Historical Society of Germans from Russia, 1999): Sm19.