RAND Publications - free downloads

The RAND corporation publishes a number of reports and books and makes, as far as I can tell, most of them freely available as downloads.  They're a 501(c)(3) non-profit organization and have done research on a broad range of defense, technical and social issues. Here's their online bookstore: http://www.rand.org/pubs/ And better yet, here's a link that returns all of their submarine reports: RAND submarine reports