Tài liệu tham khảo

WikiPedia: Nhóm_ngôn_ngữ_Bihar http://www.diehardindian.com/history-of-indian-lan... http://www.ethnologue.com/19/country/IN/languages/ http://www.ethnologue.com/language/anp http://www.censusindia.gov.in/2011Census/Language_... http://india.gov.in/my-government/constitution-ind... http://glottolog.org/resource/languoid/id/biha1245 https://books.google.com/books?id=NNMvAAAAYAAJ&pri... https://books.google.com/books?id=dtKe6XV8z7wC&pg=... https://m.livehindustan.com/jharkhand/story-maithi... https://www.thehindu.com/todays-paper/tp-in-school...