According to the ESRI website, the "bibliography covers the literature of geographic information systems, science, and technology. It indexes journals, conference proceedings, books, and reports from the origins of GIS to the present. There are currently 109,928 entries in the Esri GIS Bibliography."
From USGS, "The National Map is a collaborative effort among the USGS and other Federal, State, and local partners to improve and deliver topographic information for the Nation." Includes downloadable data.