2019년 12월 Album Chart [December 2019 Album Chart]. Gaon Music Chart (in Korean). Retrieved January 9, 2020.
insight.co.kr
Kwon, Gil-yeo (March 3, 2019). 아이유, 곧 컴백한다 “새 앨범 준비 중” [IU, comeback soon "Preparing for a new album"]. Insight (in Korean). Retrieved August 12, 2020.