Erna (akụkọ ifo)

N'ime akụkọ ifo Norse dịka uri Eddic Rígsþula siri dị, Erna bụ nne nke ụmụ nwoke iri na abụọ nke Jarl, [1] bụ ndị nna ochie nke klaasị ndị dike na obodo Norse.  Nna ya bụ Hersir, onye isi ebo.

 Edensibia 

 Dugdale-Pointon, TDP  (21 Machị 2001), Hersir, Viking, *http://www.historyofwar.org/articles/weapons_hersir.html
 https://web.archive.org/web/20080725032556/http://www.cybersamurai.net/Mythology/nordic_gods/LegendsSagas/Edda/PoeticEdda/Rigsthula.htm