Although in ordinary academic parlance a monograph is understood to be a specialist academic work, rather than a reference work on a single scholarly subject, in library and information science monograph denotes more broadly any non-serial publication complete in one volume (book) or a finite number of volumes (even a novel like Proust’s seven-volume In Search of Lost Time), in contrast to serial publications like a magazine, journal, or newspaper. An avid reader or collector of books is a bibliophile or colloquially, “bookworm”. A shop where books are bought and sold is a bookshop or bookstore. Books are also sold elsewhere. Books can also be borrowed from libraries. Google has estimated that as of 2010, approximately 130,000,000 distinct titles had been published. In some wealthier nations, the sale of printed books has decreased because of the increased usage of e-books.