Analysis of information sources in references of the Wikipedia article "Horses in ancient and Imperial China" in English language version.
[...] there does not seem to be any indisputable material evidence for chariots from the eastern part of the Northern Zone until the very end of the second or the beginning of the first millennium BC. [...] chariots probably gained privileged status among the Shang prior to their introduction to politically important regions further east and northeast [...]. [...] In China [...] this steppe technology was newly arrived and poised to have a major impact on politics, warfare, and the practice of statecraft in East Asia.