TY - RPRT TI - Circular of the Bureau of Standards no. 472: table and Mollier chart for ammonia below -60 [degrees] F AU - Meyers, Cyril H PY - 1948 PB - National Bureau of Standards CY - Gaithersburg, MD SN - NBS CIRC 472 DO - 10.6028/NBS.CIRC.472 ER -