What happened to the reference guide, "Hollow-Earth Theories: A List of References"?
The Library of Congress is completing a project to update and modernize Library reading room websites. As a part of the process, the Science Section has re-evaluated its web content, retiring older outdated guides, while updating and migrating more recent or heavily utilized guides to a new platform. A fully updated and migrated “Hollow-Earth Theories: A List of References” reference guide has now been published and and is listed among the Library's reference guides under Geography and Earth Sciences and Geology.
Links pointing to the older edition of “Hollow-Earth Theories: A List of References” have been redirected to point users to the new guide. You can, however, still access an archived version of the older edition using the Internet Archive’s Way Back Machine.