trade paperback

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A paperback book that is typically of better production quality, larger size, and higher price than a mass-market edition, intended for sale in bookstores.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A type of book whose content primarily consists of previously published material, usually originally in a periodical format, and bound together as one work, or part of a series itself.