TY - RPRT TI - Procedures for precise determination of thermal radiation properties: progress report no. 31 Feb. 1, 1966 - July 31, 1966 PY - 1966 PB - National Bureau of Standards CY - Gaithersburg, MD SN - NBS RPT 9407 DO - 10.6028/NBS.RPT.9407 ER -