Sung Si-kyung Grateful for Support Amid Manager Betrayal  조선일보7 Celebrities Who Were Betrayed by Their Managers and Close Friends: Sung Si Kyung, Lisa, and More  ZAPZEESung Si Kyung Opens Voice About Alleged Fraud Of Former Manager  VOI.IDSung Si-kyung keeps his promise to fans after manager’s betrayal  The Korea TimesSung Si-kyung Says, “I’m Okay, I Came to Check My Voice” — First Public Appearance After Financial Loss from Former Manager  매일경제