Leading print-on-demand publisher Author Solutions has bought rival Xlibris, the WSJ reports. Terms of the deal weren’t disclosed. Bloomington, Ind.-based Author Solutions runs self-publishing units AuthorHouse and iUniverse. Combined, the three have released 19,000 titles last year. Philadelphia-based Xlibris has issued 20,000 titles since forming about a decade ago. It’s backed by Bertelsmann AG’s Bertelsmann Digital Media Investments.