Widow Gertrude Jagtmann is recorded on the 1798 census of Nieder-Monjou in Household No. Nm62.
There are no known surviving male lines of this 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): Nm62.