TY - RPRT TI - Circular of the Bureau of Standards no. 539 volume 2: standard x-ray diffraction powder patterns AU - Swanson, Howard E PY - 1953 PB - National Bureau of Standards CY - Gaithersburg, MD SN - NBS CIRC 539v2 DO - 10.6028/NBS.CIRC.539v2 ER -