Jerka [ˈjɛrka] is a village in the administrative district of Gmina Krzywiń, within Kościan County, Greater Poland Voivodeship, in west-central Poland. It lies approximately 5 kilometres (3 mi) north-east of Krzywiń, 17 km (11 mi) south-east of Kościan, and 45 km (28 mi) south of the regional capital Poznań. References. https://en.wikipedia.org/wiki/Jerka