What is a Bookshelf in Google Books?

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A Bookshelf is a collection of books within your Google Books Library that have a common topic or basis for interest. Just as you might group all your physical books about, say, Abraham Lincoln together on a physical shelf (or in this case, a tower), you can make a list of books that have something in common into a Bookshelf.

My Google Books Shelf Search tool was built to offer a way to search a keyword within books on a Bookshelf.