Lubotsky, Alexander, The Indo-Iranian substratum(PDF), Carpelan, Christian (编), Early Contacts between Uralic and Indo-European: Linguistic and Archaeological considerations. Papers presented at an international symposium held at the Tvärminne Research Station of the University of Helsinki 8–10 January 1999 (PDF)使用|format=需要含有|url= (帮助), Asko Parpola, Petri Koskikallio, Helsinki, Finland: Finno-Ugrian Society: 301–317, 2001 [2011-03-22], (原始内容存档(PDF)于2008-04-11)
Lubotsky, Alexander, The Indo-Iranian substratum(PDF), Carpelan, Christian (编), Early Contacts between Uralic and Indo-European: Linguistic and Archaeological considerations. Papers presented at an international symposium held at the Tvärminne Research Station of the University of Helsinki 8–10 January 1999 (PDF)使用|format=需要含有|url= (帮助), Asko Parpola, Petri Koskikallio, Helsinki, Finland: Finno-Ugrian Society: 301–317, 2001 [2011-03-22], (原始内容存档(PDF)于2008-04-11)