Analysis of information sources in references of the Wikipedia article "Devanagari" in Vietnamese language version.
... an early branch of this, as of the fourth century AD, was the Gupta script, Brahmi's first main daughter... the Gupta alphabet became the ancestor of most Indic scripts (usually through later Devanagari)... Nagari, of India's north-west, first appeared around AD 633... in the eleventh century, Nagari had become Devanagari, or 'heavenly Nagari', since it was now the main vehicle, out of several, for Sanskrit literature...
... In the Kutila this develops into a short horizontal bar, which, in the Devanagari, becomes a continuous horizontal line... three cardinal inscriptions of this epoch, namely, the Kutila or Bareli inscription of 992, the Chalukya or Kistna inscription of 945, and a Kawi inscription of 919... the Kutila inscription is of great importance in Indian epigraphy, not only from its precise date, but from its offering a definite early form of the standard Indian alphabet, the Devanagari...
