TY - RPRT TI - Development of methods of test for quality control of porcelain enamels: progress report January 1 through March 31, 1970 AU - Burdick, M D PY - 1970 PB - National Bureau of Standards CY - Gaithersburg, MD SN - NBS RPT 10225 DO - 10.6028/NBS.RPT.10225 ER -