TY - RPRT TI - Collaborative reference program for paper : Report no. 49G AU - Powell, R G AU - Randall, E B AU - Horlick, J PY - 1977 PB - National Bureau of Standards CY - Gaithersburg, MD SN - NBS IR 77-1322 DO - 10.6028/NBS.IR.77-1322 ER -