Restrictions on Systematic Downloading of NASA STI
Crawlers and other automated processes may not be used to systematically retrieve batches of STI from the NTRS website.
Bulk downloading of STI is prohibited because of potential copyright restrictions.
Please note that the copyright status is indicated in the metadata of the documents.
NTRS has an auxiliary harvesting mechanism that may be used, which is the Open Archives Initiative Protocol for Metadata Harvesting (OAI-PMH).
See https://www.sti.nasa.gov/harvesting-data-from-ntrs and contact the Information Desk for details.
Do not use any other automated processes for bulk downloading.