L. Winifred Faraday, The Edda, Volume 1
“ This, however, is true of other Gods, notably of Tyr, who is without question one of the oldest. The only deities named with any suggestion of sacrifice or worship in the Icelandic sagas proper are Odin, Thor, Frey, Njörd, Frigg and Freyja. The process of choice is as arbitrary in mythology as in other sciences. Again, it is more likely that the original version of the legend should have survived in Iceland than in Denmark, which, being on the mainland, was earlier subject to Christian and Romantic influences ”
