The '' Primer '' became designated as the first official Los Alamos technical report ( LA-1 ) , and though its information about the physics of fission and weapon design was soon rendered obsolete , it is still considered a fundamental historical document in the history of nuclear weapons . Its contents would be of little use today to someone attempting to build a nuclear weapon , a fact acknowledged by its complete declassification in 1965 . It used to be available for download from Los Alamos 's website , but after the September 11 attacks , Los Alamos restricted access to all of their technical reports . It can still be found on internet mirrors , though , as well as on Wikipedia
September 11 attacks
September 11 attacks
Los Alamos Primer