TY - RPRT TI - Circular of the Bureau of Standards no. 2 4th edition: measurements of length and area, including thermal expansion AU - Stratton, S W PY - 1912 PB - National Bureau of Standards CY - Gaithersburg, MD SN - NBS CIRC 2e4 DO - 10.6028/NBS.CIRC.2e4 ER -