This gazetteer of the Republic of Poland from 1933 is valuable because it is a single resource for all of Poland back then. Prior to the restoration of the Polish state, you often needed a different gazetteer specific for the partition you were working in. Furthermore, modern gazetteers do not include the eastern territory that was taken from Poland after World War II. This gazetteer includes the parish that a locality belonged to so you know where to looks for parish records.