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

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ETYMOLOGY

HAN VIET: công nguyên 公元

KOREAN 3.0	Eng	Wordtype	Etym.	Gb	Vie
☆☆	ORIGIN; BEGINNING	Noun	纪元	公元	công nguyên
☆	B.C.	Noun	纪元前	公元前	trước công nguyên
☆	A.D.	Noun	纪元后	公元后	sau công nguyên