How many scholarly papers are on the Web? At least 114 million, professor finds | Penn State University

"Lee Giles, a professor at Penn State’s College of Information Sciences and Technology (IST), has devoted a large portion of his career to developing search engines and digital libraries that make it easier for researchers to access scholarly articles. While numerous databases and search engines track scholarly documents and thus facilitate research, many researchers and academics are concerned about the extent to which academic and scientific documents are available on the Web as well as their ability to access them. As part of an effort to make the process of accessing documents more efficient, Giles recently conducted a study of two major academic search engines to estimate the number of scholarly documents available on the Web ..."