Balthasar Jerkop, a farmer, his wife Elisabeth, and children (Johann Adam, age 12; Margaretha, age 11) are recorded on the 1767 census of Semenovka in Household No. 25. They had settled there on 24 July 1767.
The 1767 census records that Balthasar Jerkop came from the German village of Robsteis [?] in the Fulda region.
- Pleve, Igor. Einwanderung in das Wolgagebiet, 1764-1767 Band 4 (Göttingen: Göttinger Arbeitskreis, 2008): 184.