Stalin's Captive: Nikolaus Riehl and the Soviet Race for the Bomb - Nikolaus Riehl, Frederick Seitz - Google Books

http://books.google.de/books/about/Stalin_s_captive.html?id=EC2aAAAAIAAJ&redir_esc=y

"This historic book . . . presents Riehl's absorbing account of his key role in the production of pure uranium for . . . the Soviet nuclear bomb program [and], written by uniquely qualified Frederick Seitz, an extraordinary and perceptive…