@misc{indiciaeaf540b48e4cd,
  title = {An improved phase-contrast microscope with variable amplitude and phase difference.},
  author = {B O PAYNE},
  year = {1954},
  doi = {10.1111/j.1365-2818.1954.tb02008.x},
  url = {https://pubmed.ncbi.nlm.nih.gov/13212798/},
  note = {Source identifier: 13212798}
}