^ Weiss, Michael (2006) “Latin Orbis and its Cognates”, in Historische Sprachforschung[1], volume 119, Vandenhoeck & Ruprecht, →ISSN, →JSTOR, pages 250–272
^ "Hittite ḫarp(p)- and Derivatives". Investigationes Anatolicae: Gedenkschrift für Erich Neu, edited by J. Klinger, E. Rieken, C. Rüster.