f(x) - Beautiful Stranger (by f(Amber+Luna+Krystal))
에프엑스 f(x) - Goodbye Summer (f(Amber+Luna+Krystal)) (Feat. D.O. of EXO-K)
f(x) - Beautiful Stranger (f(Amber+Luna+Krystal)) (Instrumental)
f(x) Luna, Krystal - Calling Out
f(x)에프엑스 - Beautiful Stranger (f(Amber+Luna+Krystal))
f(x) - You Are My Destiny (Luna+Krystal)
F(x) Krystal & Luna - Hard but easy
f(x) (Amber, Luna, Krystal) (ft. D.O of EXO-K) - Goodbye Summer
Krystal & Luna - F(x)에프엑스 - Sorry
F(x) Krystal & Luna - Hard but easy
f(x)'s Amber Luna Krystal Feat. D.O. of EXO-K - Goodbye Summer
f(x) (Krystal & Luna) - Sorry (Dear. Dad)
F(x) Krystal & Luna - Hard but easy (OST Invincible Lee Pyung Kang)
Amber, Luna, Krystal[F(x)] - Beautiful Stranger
Krystal & Luna F(x) - Hard And Easy
Amber, Luna, Krystal (f(x)) ft. D.O (EXO) - Goodbye summer
f(x)'s Amber Luna Krystal Feat. D.O. of EXO-K - Goodbye Summer т,п
f(x)'s Amber Luna Krystal Feat. D.O. of EXO-K - Goodbye Summer
f(x) (에프엑스) (Amber, Luna, Krystal) Feat. D.O. of EXO-K - 07. Goodbye Summer (Pink Tape, 2013)