↑ 1,01,1Michiel de Vaan. Etymological Dictionary of Latin and the Other Italic Languages. Página 585. Editorial: Leiden. Brill, 2008. ISBN: 9789004167971.
↑ 2,02,12,22,32,42,52,62,7Oxford Latin Dictionary. Editado por: P. G. W. Glare. Editorial: Oxford University Press. Oxford, 1983.