Several years later, he offered a number of lexical and phonological correspondences between the North Caucasian, Salishan, and Wakashan languages, concluding that Salishan and Wakashan may represent a distinct branch of North Caucasian and that their separation from it must postdate the dissolution of the Northeast Caucasian unity (Avar-Andi-Tsezian), which took place around the 2nd or 3rd millennium BC.
sˈɛvɹəl jˈɪɹz lˈeɪɾɚ, hiː ˈɔfɚd ɐ nˈʌmbɚɹ ʌv lˈɛksɪkəl ænd fˌɑːnəlˈɑːdʒɪkəl kˌɔːɹɪspˈɑːndənsᵻz bᵻtwˌiːn ðə nˈɔːɹθ kɔːkˈeɪʒən, sˈælɪʃən, ænd wˈækæʃən lˈæŋɡwɪdʒᵻz, kəŋklˈuːdɪŋ ðæt sˈælɪʃən ænd wˈækæʃən mˈeɪ ɹˌɛpɹᵻzˈɛnt ɐ dɪstˈɪŋkt bɹˈæntʃ ʌv nˈɔːɹθ kɔːkˈeɪʒən ænd ðæt ðɛɹ sˌɛpɚɹˈeɪʃən fɹʌm ɪt mˈʌst poʊstdˈeɪt ðə dˌɪsəlˈuːʃən ʌvðə nˈɔːɹθiːst kɔːkˈeɪʒən jˈuːnɪɾi ˈævɑːɹɹˈænditsˈɛziən, wˌɪtʃ tˈʊk plˈeɪs ɚɹˈaʊnd ðə sˈɛkənd ɔːɹ θˈɜːd mɪlˈɛniəm bˌiːsˈiː.