@misc{indiciae79026086b3bb,
  title = {The Polanret variable densiphase microscope.},
  author = {O W Richards},
  year = {1973},
  doi = {10.1111/j.1365-2818.1973.tb03805.x},
  url = {https://pubmed.ncbi.nlm.nih.gov/4592809/},
  note = {Source identifier: 4592809}
}