Chosŏn chʻogi yeak ŭi yŏnʼgu: kŭ chŏngbi, naeyong, ŭiŭirŭl chungsim ŭro - Chʻoe, Chŏng-yŏ (Kyemyŏng taehak chʻulpʻanbu, 1975)
In Korean. - Includes english summary