Florian Kotzur and Stefan Krumpen at their exhibit at the regional contest "Schüler experimentieren" (source: ThyssenKrupp Services AG) | Stefan Krumpen and Florian Kotzur at the state contest "Schüler experimentieren" at RWE in Bochum | Stefan Krumpen and Florian Kotzur with their supervisor Andrea Frick at the state contest |