Today we think of Wikipedia as the source of all information, the ultimate reference. Yet it is just the latest in a long line of aggregated knowledge--reference works that have shaped the way we've seen the world for centuries. You Could Look It Up chronicles the stories behind these great works and their contents, and the way they have influenced each other. Jack Lynch illuminates the human stories behind these great works, as well as their enduring impact on civilization. In the process, he offers new insight into the value of knowledge.