Jeong, Ji-won (September 21, 2023). 웨이크원, 김재환 활동 모두 전담 "10월 亞공연·12월 컴백"(공식) [Wake One, in charge of all Kim Jae-hwan's activities, "Performance in October, Comeback in December" (Official)]. Joy News 24 (dalam bahasa Korea). Dicapai pada September 21, 2023.
Kim, Hyun-sik (October 22, 2021). "김채현 1위…'걸스플래닛' 9인조 걸그룹 '케플러' 결성". Edaily (dalam bahasa Korea). Diarkibkan daripada yang asal pada October 22, 2021. Dicapai pada October 22, 2021.
Kim, Hyun-sik (October 22, 2021). "김채현 1위…'걸스플래닛' 9인조 걸그룹 '케플러' 결성". Edaily (dalam bahasa Korea). Diarkibkan daripada yang asal pada October 22, 2021. Dicapai pada October 22, 2021.