西河旧事 (西河舊事) xī hé jiù shì

xī hé jiù shì proper noun Reminiscence of Xi He
Domain: History 历史 , Subdomain: China , Concept: Book Title 书名
Notes: A historic text with records of the Xiongnu, now lost but quoted by later Chinese scholars (Gan 2020, p. 186; Rong 2013, p. 20; Wikipedia '西河舊事')