1. What countries have the most languages? https://www.ethnologue.com/guides/countries-most-languages
2. Indo-Aryan languages. https://www.britannica.com/topic/Indo-Aryan-languages
3. Dravidian languages. https://www.britannica.com/topic/Dravidian-languages
4. Moseley C (2008) Encyclopedia of the world’s endangered languages. Routledge, London
5. Census of India—Language. https://censusindia.gov.in/2011Census/C-16_25062018_NEW.pdf