Bochum, North Rhine-Westphalia, Germany
Gelsenkirchen, Nordrhein-Westfalen, Germany
Essen, North Rhine-Westphalia, Germany
Villingen-Schwenningen, Baden-Württemberg, Germany
Zürich, Zürich, Switzerland
Gelsenkirchen, North Rhine-Westphalia, Germany
Graz, Styria, Austria
Weihai, Shandong, China
Bregenz, Vorarlberg, Austria
Reinach, Aargau, Switzerland
Frankfurt, Hessen, Germany