TY - GEN AU - M Ehrlich C2 - , National Institute of Standards and Technology, Gaithersburg, MD DA - 1959-01-01 05:01:00 DO - https://doi.org/10.6028/NBS.TN.29 LA - en PB - , National Institute of Standards and Technology, Gaithersburg, MD PY - 1959 TI - Photographic dosimetry at total exposure levels below 20 mr: ER -