Ernst Sonntag (age 18) and his siblings (Magdalena, age 12; Mattias, age 8) are recorded on the 1767 census of Brabander in Household No. 95 along with their stepfather Mattias Sturm. They had settled there on 19 August 1767.
The 1767 census does not record from where the Sonntag children came.
- Pleve, Igor. Einwanderung in das Wolgagebiet, 1764-1767 Band 1 (Göttingen: Göttinger Arbeitskreis, 1999): 235.