RT Journal Article SR Electronic T1 Permissible Dose: A History of Radiation Protection in the Twentieth Century JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 281 OP 283 VO 43 IS 2 A1 Dennis D. Patton YR 2002 UL http://jnm.snmjournals.org/content/43/2/281.abstract AB