The site for this three volume work, while not reproducing the entries, does provide an A-Z list of the articles and includes the supporting bibliographies, most of which have some annotations. From “Collections of Travel and Exploration” to the “Rocky Mountains,” a reader can readily identify the primary/secondary sources associated with each topic. In combination with a site such as HathiTrust, one can retrieve much of the original source documentation online. A good place to start one’s research.
Literature of Travel and Exploration: An Encyclopedia