TY - RPRT TI - Standard Reference Materials : Preparation of NBS copper-base spectrochemical standards/ AU - Wyman, LeRoy L AU - Michaelis, Robert E PY - 1964 PB - National Institute of Standards and Technology CY - Gaithersburg, MD SN - NBS SP 260-2 DO - 10.6028/NBS.SP.260-2 ER -