^ Cheung, Johnny (2007) “*hu̯anH”, in Etymological Dictionary of the Iranian Verb (Leiden Indo-European Etymological Dictionary Series; 2), Leiden, Boston: Brill, →ISBN, pages 144-145
↑ 2.02.1Derksen, Rick (2008) “*zvȏnъ”, in Etymological Dictionary of the Slavic Inherited Lexicon (Leiden Indo-European Etymological Dictionary Series; 4), Leiden, Boston: Brill, →ISBN, →ISSN, page 550
↑ 3.03.1De Vaan, Michiel (2008) “sonō, -āre”, in Etymological Dictionary of Latin and the other Italic Languages (Leiden Indo-European Etymological Dictionary Series; 7), Leiden, Boston: Brill, →ISBN, page 574
↑ 7.07.1Schrijver, Peter C. H. (1991) The reflexes of the Proto-Indo-European laryngeals in Latin (Leiden studies in Indo-European; 2), Amsterdam, Atlanta: Rodopi, →ISBN