Analysis of information sources in references of the Wikipedia article "Northeast Caucasian languages" in English language version.
theories relating Caucasian with […] the non-Indo-European and non-Semitic languages of the ancient Middle East also lack sufficient evidence and must be considered as inconclusive
Sayce, for example, considered a relationship with Georgian, 'or with any of the Caucasian languages such as Ude or Abkhas,' but admitted he lacked the tools to explore this. […] That Hurro-Urartian as a whole shared a yet earlier common ancestor with some of the numerous and comparatively obscure languages of the Caucasus is not improbable. […] Diakonoff and Starostin, in the most thorough attempt at finding a linkage yet published, have argued that Hurro-Urartian is a branch of the eastern Caucasian family […]. The etymologies, sound correspondences, and comparative morphologies these authors present are quite tentative and viewed with skepticism by many.