Yi, Jeong-hyeok (October 30, 2014). 걸그룹 스피카, 완전체로 컴백. 신곡 '고스트' 5일 공개 [Girl group Spica is making a comeback with a full lineup. New song 'Ghost' released on the 5th] (in Korean). Sports Chosun. Retrieved November 5, 2014.
Bak, Su-jeong (November 5, 2014). 스피카, 스페셜 싱글 '고스트' 공개..리얼 삼각관계 뮤직비디오 눈길 [Spica unveils special single 'Ghost'..Real love triangle music video attention] (in Korean). TenAsia. Archived from the original on November 29, 2014. Retrieved November 5, 2014.
Bak, Su-jeong (November 5, 2014). 스피카, 스페셜 싱글 '고스트' 공개..리얼 삼각관계 뮤직비디오 눈길 [Spica unveils special single 'Ghost'..Real love triangle music video attention] (in Korean). TenAsia. Archived from the original on November 29, 2014. Retrieved November 5, 2014.