허저족 Hŏjŏjok 아무르강 의 어렵민 Amurŭgang ŭi ŏryŏmmin (Tongbuga Yŏksa Chaedan kihoek yŏn'gu; Chungguk Tongbuk chiyŏk minjok munhwa yŏn'gu, 2017)