목차

II. 모음사각도 Day1, 2, 3

https://hun-min.com/2023/07/03/vowel-quadrilateral-day123/

III. 方合 三合 六合 6해 6충 6파

21세기 훈민정음의 미래

https://hun-min.com/2023/07/03/future-of-hunminjeongeum-21c/