TY - RPRT TI - Justification of Shielding Requirements for Plutonium Sources AU - Pibida, L. AU - Unterweger, M PY - 2012 PB - National Institute of Standards and Technology CY - Gaithersburg, MD SN - NIST TN 1758 DO - 10.6028/NIST.TN.1758 ER -