Комментарии:VEWT 205 (Turk.-Mong.), АПиПЯЯ 287. The Turkic form may belong here if PT *jogan < *jojga-n. The Japanese form goes back to an intermediate variant *ǯi̯oč`u-k`a (with assimilative devoicing of *-ǯ-). Korean has a frequent verbal low tone.
