Some scholars – most notably Lajos Ligeti (1950/51) and Edwin G. Pulleyblank (1962) – have claimed that languages of Siberia, especially Ket – a member of the Yeniseian language family – may have been a major source (or perhaps even the linguistic core) of the Xiongnu and/or Hunnic languages. First proposed by Edwin G. Pulleyblank, the theory that the Xiongnu language belonged to the Yeniseian languages was reinforced by the discovery of the Kot and Pumpokol word lists, which Alexander Vovin used to create a more accurate reconstruction. Hyun Jin Kim in 2013 proposed that the Huns experienced a language flip like the Chagatai Khanate, switching from Yeniseian to Oghuric Turkic after absorbing the Dingling or Tiele peoples.