soft-cover

1. Paper back: Booksellers 'term to mean soft-cover book as distinguish form hard-cover book. Case-bound book: A term used to denote a book bound with a stiff or hard cover.
   普及本：是书商用名词，意指平装本，有别于精装本。精装本：结实和硬皮装订的书箱。

noun

1. a book with paper covers

   Synonym:    paperback bookpaper-back bookpaperbacksoftback booksoftbacksoft-cover book