"가수 보아 첫 디지털싱글'Key of Heart'국내 발매" [Singer BoA’s first digital single ‘Key of Heart’ released in Korea]. Herald Biz (in Korean). Naver. September 19, 2006. Retrieved January 20, 2024.
"보아, 日20번째 싱글 국내발매" [BoA, Japan's 20th single released domestically]. Star News (in Korean). Naver. October 23, 2006. Retrieved January 20, 2024.
"동방신기·신화, 오리콘차트 나란히 3·4위" [TVXQ and Shinhwa ranked 3rd and 4th on the Oricon chart]. Spots Kyunghyang (in Korean). Naver. August 10, 2006. Retrieved January 20, 2024.