From NTIS:
The National Technical Reports Library (NTRL) is now offering the American public free public access to a searchable online database of approximately three million federal science and technology reports.
The library is a service of the U.S. Commerce Department’s National Technical Information Service.
NTIS, a federal agency that does not receive appropriations from Congress, previously charged a fee to provide full-text electronic copies of federal documents in its collection.
The full text for 800,000 of these documents can be downloaded immediately in electronic PDF format without charge. The remaining NTRL reports, most published before 1995, must be scanned from microfiche archival files before being provided either as electronic PDF’s or in print for a fee. However, each time a microfiche document is scanned to fulfill such a request, the agency will add the electronic full-text PDF to its online database for subsequent free public download.
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The agency will also continue to offer a range of premium subscription-based services to individuals, universities, corporations, and other institutions for varying levels of access to all documents in its collection. Access outside the U.S. is available via individual and institutional subscriptions.
See Also: TRAIL (Technical Report and Archive Image)
From the U. of Washington. Search and access U.S. government technical reports primarily prior to 1976 and digitized by TRAIL.