Ko, Ik-chin.

• Aham pŏpsang ŭi chʻegyesŏng yŏnʼgu
• Hanʼguk chʻansul Pulsŏ ŭi yŏnʼgu
• Hanʼguk kodae Pulgyo sasangsa
• Hanʾguk ŭi Pulgyo sasang
• Hyŏndae Hanʼguk Pulgyo ŭi panghyang
• Pulgyo ŭi chilligwan