^Stwertka, Albert (2018). A guide to the elements (4. bas.). New York, NY: Oxford University Press. ISBN978-0190682347.
^Roger D. Woodard (2008). The Ancient Languages of Asia and the Americas. Cambridge University Press. ss. 1-2. ISBN978-0-521-68494-1. 20 Ağustos 2020 tarihinde kaynağından arşivlendi. Erişim tarihi: 10 Ocak 2020., Quote: "The earliest form of this 'oldest' language, Sanskrit, is the one found in the ancient Brahmanic text called the Rigveda, composed c. 1500 BC. The date makes Sanskrit one of the three earliest of the well-documented languages of the Indo-European family – the other two being Old Hittite and Myceanaean Greek – and, in keeping with its early appearance, Sanskrit has been a cornerstone in the reconstruction of the parent language of the Indo-European family – Proto-Indo-European."