The widow and daughter of Peter Wertz are recorded on the 1798 census of Kraft in Household No. Kf24.
There are no known surviving male lines of this Wertz family among the Volga German colonies.
- 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): Kf24.