TY  - RPRT
TI  - Letter Circular 17 (Communication B514): explanation of drawings used in manufacture of pitch testing devices
PY  - 1919
PB  - National Institute of Standards and Technology
CY  - Gaithersburg, MD
SN  - LCIRC 17
DO  - 10.6028/NBS.LCIRC.17
ER  -