Karl Jänike and his family are recorded on the 1798 census of Biberstein in Household No. Bb43.
The death of Karl Jänike in 1823 is recorded on the 1834 census of Biberstein in Household No. 29.
- 1834 Biberstein Census (Household No. 29).
- Mai, Brent Alan. 1798 Census of the German Colonies along the Volga (Lincoln, NE: American Historical Society of Germans from Russia, 1999): Bb43.