鲜为人知 (鮮為人知) xiān wéirén zhī

xiān wéirén zhī set phrase rarely known to anyone; almost unknown; secret to all but a few
Domain: Idiom 成语
Notes: (CC-CEDICT '鮮為人知')

Contained in

• 毛泽东·鲜为人知的故事(毛澤東·鮮為人知的故事) Mao: The Unknown Story by Jung Chang 張戎|张戎 and Jon Halliday