by 종상가성비교류회
https://www.youtube.com/watch?v=s8avXQ2V-UY
ppt:
ppt: https://docs.google.com/presentation/d/1gWdmnLo48SI4iBiR8NmM5UGf8nSSY-BOWAc3RPdvk5U/edit#slide=id.p
https://youtu.be/T60pthgiGTY?si=v--0VipvGkZMUZGw
