1. “Osukche Song Ikhŭm ŏn'gan sŏch'e ŭi hyŏngsŏng kwa chohyŏngsŏng koch'al” [The formation and style of Song Ikhŭm's calligraphy in his letters in the vernacular Korean script];Poktong;Sŏyehak yŏn'gu,2013
2. Chosŏn sidae hanmun kanch'al ŭi sŏyesa chŏk ŭiŭi” [The calligraphic significance of literary Chinese epistles in Chosŏn dynasty];Insuk;Sŏyehak yŏn'gu,2005
3. “17 segi sangch’ŭng yŏsŏng ŭi kungmun saenghwal e kwanhan munhŏn chŏk koch'al” [Overview of sources on women's use of vernacular Korean script in the seventeenth century];Kyŏngha;Han'guk munhak nonch'ong,2005