Dyakova, O. V. (2005). Gorodischa i kreposti Dalnego Vostoka (severovostochnoye primorye). (Ancient Town Sites and Fortresses of Far East. (Northeastern Primorye)). Vladivostok, 171.
 Nosov, K. S. (2001). Zamki i kreposti Indii, Kitaya i Japonii (Castles and Fortresses of China and Japan). Rejttarj, Moscow, 27.
 Un, K. G. (2005). Research of Particulariries of Koguryo Mountain Towns (pp. 138-152). Separately printed copy. Similar characterization of Koguryo towns was offered by Prof. Nam Il Ren, University Kim Il Sung, at Second International Conference on Korean Studies.