1 (wiktionary) 2 (vi.wikipedia) 3 (en.wikipedia) 4 (glosbe)

Core Words Familarize yourself with the 'core words'.
Compounds Expand your vocabulary by studying more complex words built by the 'core words'.
Wordsense Learn about the wordsenses of the english term.

ETYMOLOGY

HAN VIET: thư diện 书面

KOREAN 3.0	Eng	Wordtype	Etym.	Gb	Vie
☆	WRITTEN FORM	Noun	书面	书面	văn bản
☆	WRITTEN LANGUAGE	Noun	文语	书面语	văn viết