充栋汗牛 (充棟汗牛) chōng dòng hàn niú

chōng dòng hàn niú set phrase enough books to fill a house to the rafters or to make a pack-ox sweat
Domain: Idiom 成语
Notes: (CC-CEDICT '充棟汗牛'; Guoyu '充棟汗牛')