@article{39731,
  author = {C O'Brien and C. Kessler and D Burns},
  title = {Key comparison BIPM.RI(I)-K7 of the air-kerma standards of the NIST, USA and the BIPM in mammography x-rays.},
  year = {2011},
  number = {0612},
  month = {2011-08-01},
  publisher = {Metrologia},
  language = {en},
}