Reinhard Opfermann, a farmer, and his wife Christina are recorded on an appendix to the 1767 census of Nieder-Monjou in Household No. 115.
The movement tables attached to the 1767 census of Schönchen record the movement of Reinhard Opferman and his family in 1774 from Schönchen to St. Petersburg.
- 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): Mv2596.
- Pleve, Igor. Einwanderung in das Wolgagebiet, 1764-1767 Band 3 (Göttingen: Göttinger Arbeitskreis, 2005): 224.