TY - GEN AU - Waters, C E C2 - , National Institute of Standards and Technology, Gaithersburg, MD DA - 1940-01-01 05:01:00 DO - https://doi.org/10.6028/NBS.CIRC.426 LA - en PB - , National Institute of Standards and Technology, Gaithersburg, MD PY - 1940 TI - Circular of the Bureau of Standards no. 426::inks ER -