TY - RPRT TI - Letter Circular 276: railroad track scale testing service of the U.S. Bureau of Standards during the fiscal year July 1, 1928 to June 30, 1929 PY - 1929 PB - National Institute of Standards and Technology CY - Gaithersburg, MD SN - LCIRC 276 DO - 10.6028/NBS.LCIRC.276 ER -