Ferlus (2009) showed that the inventions of pestle, oar, and a pan to cook sticky rice, which is the main characteristic of the Đông Sơn culture, correspond to the creation of new lexicons for these inventions in Northern Vietic (Việt–Mường) and Central Vietic (Cuoi-Toum). The new vocabularies to denote these inventions were proven to be derivatives from original verbs rather than borrowed lexical items. The current distribution of Northern Vietic also correspond to the area of Dong Son culture. Thus, Ferlus conclude that the Dongsonian culture was of Vietic origin and they were the direct ancestors of modern Vietnamese people.