Комментарии:KW 360, АПиПЯЯ 73, 83, 87, 276 (confused with the reflexes of *si̯uru q. v.), Лексика 182, Whitman 1985, 168. In Turkic a secondary narrowing (*sirke < *serke or *si̯arke) occurred. Mong. may be < Turkic. In Kor. we have to suppose *si̯àjri > *hjǝ̀ (with tone modified because of contraction).