← People Tjeerd de Graaf Research areas 復興・教育2比較・系統2 Find more CiNii ⌕ ↗Google Scholar ⌕ ↗ Sources 2013 Documentation and Revitalization of Two Endangered Languages in Eastern Asia: Nivkh and Ainu Article Author2013 Documentation and revitalisation of two endangered languages in eastern Asia: Nivkh and Ainu Article Author