Semi-micro prothrombin time test chamber.

@article{Mccormick1967SemimicroPT,
  title={Semi-micro prothrombin time test chamber.},
  author={Joseph B Mccormick and J B Kopp},
  journal={Technical bulletin of the Registry of Medical Technologists},
  year={1967},
  volume={37 10},
  pages={251-8}
}