Analysis of information sources in references of the Wikipedia article "Rigveda" in English language version.
The importance of the Rigveda for the study of early Indo-Aryan historical linguistics cannot be underestimated. ... its language is ... notably similar in many respects to the most archaic poetic texts of related language families, the Old Avestan Gathas and Homer's Iliad and Odyssey, respectively the earliest poetic representatives of the Iranian and Greek language families. Moreover, its manner of preservation, by a system of oral transmission which has preserved the hymns almost without change for 3,000 years, makes it a very trustworthy witness to the Indo-Aryan language of North India in the second millennium BC. Its importance for the reconstruction of Proto-Indo-European, particularly in respect of the archaic morphology and syntax it preserves, ... is considerable. Any linguistic investigation into Old Indo-Aryan, Indo-Iranian, or Proto-Indo-European cannot avoid treating the evidence of the Rigveda as of vital importance.