@misc{1160971,
  author = {James R Clifton},
  title = {Penetration resistance of concrete- a review:},
  year = {1982},
  month = {1982-01-01 05:01:00},
  publisher = {, National Institute of Standards and Technology, Gaithersburg, MD},
  doi = {https://doi.org/10.6028/NBS.SP.480-45},
  language = {en},
}