TY - RPRT TI - Letter Circular 896: standards and specifications for building and construction materials, fixtures, supplies, and equipment (superseding Letter Circular 860) PY - 1948 PB - National Institute of Standards and Technology CY - Gaithersburg, MD SN - LCIRC 896r1948 DO - 10.6028/NBS.LCIRC.896r1948 ER -