Certification of Blindness and Ascertainment of the Causes of Blindness.

@article{MackayCertificationOB,
  title={Certification of Blindness and Ascertainment of the Causes of Blindness.},
  author={George R. Mackay},
  journal={The British journal of ophthalmology},
  volume={16 4},
  pages={246-7}
}