With more than 750,000 human-edited definitions, Acronym Finder is the world's largest and most comprehensive dictionary of acronyms, abbreviations, and initialisms.
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This database provides indexing and abstracts from more than 4,000 current serial and non-serial titles, including content from AIAA and NASA.
The landmark American National Biography offers portraits of more than 17,400 men and women -- from all eras and walks of life -- whose lives have shaped the nation.
Archive Finder brings together ArchivesUSA and the cumulative index to the National Inventory of Documentary Sources in the UK and Ireland (NIDS UK/Ireland).
Online access to nearly a million descriptions of archival collections owned by thousands of libraries, museums, historical societies and archives worldwide.
Started in August 1991, arXiv.org (formerly xxx.lanl.gov) is a highly-automated electronic archive and distribution server for research articles in the areas of physics, mathematics, computer science, nonlinear sciences, quantitative biology and statistics.
Created through a partnership between NASA and the Internet Archive, NASA imagines offers public access to NASA's image, video, and audio collections in a single, searchable resource.
As of June 2, 2011, all PDF versions of books published by the National Academies Press are downloadable to anyone free of charge.
The National Ocean Service (NOS) studies, monitors, and protects coastaland marine areas in the United States.
19th Century Collections Online is a multi-year global digitization and publishing program focusing on archival collections of primary sources providing full-text, fully searchable content.