1. Die Industriestadt Wuppertal Author/Creator: Krötz, Werner Publication/Creation: Köln : Rheinland-Verlag, 1982 Resource Type: Map Access & Availability: Loading
2. Die Industriestadt Oberhausen Author/Creator: Krötz, Werner Publication/Creation: Köln : Rheinland-Verlag, 1985 Resource Type: Map Access & Availability: Loading