Xinhua News Agency «China Resurrects World's Earliest Seismograph». China Internet Information Center. Xinhua News Agency, 13-06-2013 [Consulta: 25 maig 2015]. «Others hold that all the replicas are just reconstructed from our guess and imagination rather than from our true knowledge as to how the real device used to look like. A few Western scholars even contend Zhang Heng's device was lost because it was never a reality.»
