The Romanian language has been denoted "Daco-Romanian" by some scholars because it derives from late Latin superimposed on a Dacian substratum, and evolved in the Roman colony of Dacia between AD 106 and 275. Modern Romanian may contain 160–170 words of Dacian origin. By comparison, modern French, according to Bulei, has approximately 180 words of Celtic origin.The Celtic origin of the French substratum is certain, as the Celtic languages are abundantly documented, whereas the Dacian origin of Romanian words is in most cases speculative.