汗牛充栋

汗牛充栋 [hàn niú chōng dòng]

1. ■ （形容书籍之多） (of a multitude of books) so many as to make the ox carrying them perspire and to fill a house to the rafters -- an immense number of books; enough books to make the ox carrying them sweat or to fill a house to the rafters -- an immense number of books; enough to fill the roof and cause cows to perspire before the cart -- numerous; in plenty [abundance]; overabunant