Kim, Kyu-jung
Guko Gyokwaseo jakphum Ilgi = Jung 1 si
Changbi Publishers, 2010
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Park, Jong-ho
Guko kyoswaso jakphum ilsi : jung 1 suphil
Changbi , 2011
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Seong Ha Seong
Gugeosigane Sosolilki
Buku Teks
Guko saenghwal
by Lee Sam Hyong ... [and others]
Joongang kyoyook jin heung yeongooso, 2003
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Nam, Ki-sim
Pyojun guko munpomnon
Topchulpansa, 2010
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