@misc{1191756,
  author = {Bruce L Wilson and Douglas R Tate and George Borkowski},
  title = {Circular of the Bureau of Standards no. 454::proving rings for calibrating testing machines},
  year = {1946},
  month = {1946-01-01 05:01:00},
  publisher = {, National Institute of Standards and Technology, Gaithersburg, MD},
  doi = {https://doi.org/10.6028/NBS.CIRC.454},
  language = {en},
}