TY  - RPRT
TI  - Letter Circular 14 (Communication B510): construction and operation of projection apparatus for measuring screw thread gages and profiles
PY  - 1919
PB  - National Institute of Standards and Technology
CY  - Gaithersburg, MD
SN  - LCIRC 14r1919
DO  - 10.6028/NBS.LCIRC.14r1919
ER  -