敦煌文献
The Dunhuang manuscripts represent some of the earliest examples of Tibetan writing. Several styles are represented among the manuscripts, forebears of the later Uchen (dbu can) and Ume (dbu med) styles. Both Old Tibetan and Classical Tibetan are represented in the manuscripts, as well as the undeciphered Nam language and a language that some have identified as the Zhang-zhung language.