Tài liệu tham khảo

WikiPedia: Người Slav Đông http://www.britannica.com/EBchecked/topic/548156/S... http://www.erlib.com/%D0%93%D0%B5%D0%BE%D1%80%D0%B... http://lcweb2.loc.gov/frd/cs/rutoc.html http://gumilevica.kulichki.net/VGV/vgv1.htm https://www.amazon.ca/History-Russia-Combined-Rias... https://books.google.com/books/about/A_History_of_... https://id.loc.gov/authorities/subjects/sh85123388 https://d-nb.info/gnd/4044114-3 https://web.archive.org/web/20090301173543/http://... https://web.archive.org/web/20190119174213/http://...