^ De Vaan, Michiel (2008) Etymological Dictionary of Latin and the other Italic Languages (Leiden Indo-European Etymological Dictionary Series; 7)[1], Leiden, Boston: Brill, →ISBN
^ Beekes, Robert S. P. (2010) “ῑ̓δίω”, in Etymological Dictionary of Greek (Leiden Indo-European Etymological Dictionary Series; 10), volume I, with the assistance of Lucien van Beek, Leiden, Boston: Brill, →ISBN, page 578
^ Beekes, Robert S. P. (2010) “ἱδρώς”, in Etymological Dictionary of Greek (Leiden Indo-European Etymological Dictionary Series; 10), volume I, with the assistance of Lucien van Beek, Leiden, Boston: Brill, →ISBN, pages 578-579
^ Derksen, Rick (2015) “sviedri”, in Etymological Dictionary of the Baltic Inherited Lexicon (Leiden Indo-European Etymological Dictionary Series; 13), Leiden, Boston: Brill, →ISBN, page 552