NASA Technical Reports Server (NTRS)

Additional Keywords allows you to refine your results by specifying keywords within selected fields. Available fields are displayed in the drop-down menu. [Note that results are ranked by relevancy when searching the Title, Abstract, Subject Terms, Full-Text, and All fields.]

• Use quotes to search for exact phrases (e.g., "space shuttle") or use the Advanced Search and select "Exact Phrase" from the first drop-down menu.
• Use an asterisk ( * ) as a wild card to expand term searching (e.g., comput* searches for computation, computational, computer, computers, computerization, etc.).
• Retain hyphens in words that commonly use them (e.g., x-ray).
• Search for author in several ways (e.g., "Armstrong, Neil" or "Armstrong, N.").
• Find multiple authors in one search by using last names only (e.g., Armstrong Aldrin).
• Retain all hyphens, spaces, and slashes when entering report and patent numbers (e.g., NASA-EP-251, AIAA Paper 2006-0069, NASA-Case-KSC-12246-2, NASA/SP-2005-4701).

Collection, Author, Availability Type, Document Type, NASA Center, Subject Category, and Subject Terms allow progressive refinement by browsing and selecting content features

• Click red triangles to browse and select available values.
• Click the [X] next to any value to exclude that item from your search.