Choi, Song-wu
Gugo-ui gosu.1-3
Communication Books, 2007
 Buku Referensi
Kim, Tae Gon
Gugo ohwi ui thongsijok yongu
Bogjong, 2008
 Buku Teks
Gugo Nophimbep phyohyon ui paldal 2
by Hong Jong Son ... [and others]
Doseo Chulphcn;Doseo Chulphcn, 2009
 Buku Teks
Gugo ui sije, sang, sopop : munbob ui thamgu 1
by Hong Jong Son ...[and others]
Bakmunsa, 2009
 Buku Teks
Pak, Nam-il
Choun munjang ui ssugi wihan uri mal puri sajon
Seohaemunjip, 2010
 Buku Teks