@misc{Sowa_Kazimierz_Z._Territiorial,
 author={Sowa, Kazimierz Z. and Strubelt, Wendelin},
 howpublished={online},
 title={Territiorial base of social structures. Proceedings of the sixth Polish-German Symposium on Urban and Regional Sociology, Sieniawa, July 15th to 22th 1989.},
}