Aryans in the Rigveda Quotes

“The so-called 'ruki'-law (change of s to sh after i, u, r, k) is valid for a group of the Indo-European languages, including Indo-Aryan. The occurrence of s in this position is, therefore, an indication of foreign origin. Cf. RV bisa-, kIsta-; rbIsa (cf. Panini nibirisa-), busa-, brsaya-.”
― F.B.J. Kuiper, Aryans in the Rigveda

“The question of whether the 'original' RV text had the category of retroflexes is a legitimate one but Deshpande has failed to bring forward any evidence in support of his thesis that the retroflexes are post-Rigvedic.”
― F.B.J. Kuiper, Aryans in the Rigveda

“[...] the Rigvedic society consisted of several different ethnic components, who all participated in the same cultural life. I fully agree with Southworth's words (1974: 204f.): "the equation of IA speakers with 'Aryan' (i.e. the original intruders and their direct descendants) is not supported by historical evidence.”
― F.B.J. Kuiper, Aryans in the Rigveda