Citation type for a NIST Publications
At least in my field, NIST special publications and technical notes are cited as handbooks or reports. In particular, I'd cite that as follows:


  A. Rukhin et al., "A Statistical Test Suite for Random and
  Pseudorandom Number Generators for Cryptographic Applications", NIST
  Special Publication 800-22, US Department of Commerce, National
  Institute of Standards and Technology, Gaithersburg, MD, April 2010.