Комментарии:EAS 150, Владимирцов 212, Poppe 30, 47, Мудрак Дисс. 43-44. Mong. cannot be explained as a loanword, despite Щербак 1997, 144, or as "bloßer Zufall", despite TMN 4, 288. In Kor. one has to suppose a secondary development *psɨ́r- < *spɨ́r-.