Johannes Müller is recorded on the 1798 census of Grimm in Household No. Gm010 as the son-in-law of Christian Bertel. However, the 1834 census of Grimm (Household No. 69) records that Johannes Müller was the brother-in-law of Christian Bertel.
Where these two families are recorded on the 1767 census is unknown.
- 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): Gm010.