20 Segi hanguk soseol 5
Choe Won-sik, Kim Yoo Jung, Chae Man Shik
Changbi, 2009
 Buku Teks
20 Segi hanguk soseol 7
Choe Won-sik ... [et al.]
Changbi, 2007
 Buku Teks
20 Segi hanguk soseol 4
Choe Won-sik ... [and others]
Changbi, 2009
 Buku Teks
20 Segi hanguk soseul 8 : Memilkot pil muryeob, gimgangsawa tgyosu, kkeoraei, hasudo gongsa mo beomgyeongjuk saeng
Park Yung Jun, Lee Hyo Suk, Yu Jin O, Lee Mu Yung, Park Shin Ae, Park Hwa Sung
Changbi, 2009
 Buku Teks
Choe, Won-sik
20 Segi hanguk soseul 6
Changbi, 2009
 Buku Teks