Silhak (実学) Thought on External Affairs in the Late Period of the Yi Dynasty SON Sung-ch'ol 学術雑誌目次速報データベース由来 朝鮮学報 05779766 122 0 115 143,2-3 1987 1987 110000256552 AN00146954 ENG NII-ELS 0 Silhak (実学) Thought on External Affairs in the Late Period of the Yi Dynasty SON Sung-ch'ol Journal of the Academic Association of Koreanology in Japan SON Sung-ch'ol