1. Brinkman, R., and Zijlstra, W. G., Determination and continuous registration of the percent oxygen saturation in clinical conditions, Arch. Chir. Neerl.1: 177–183, 1949.
2. Brinkman, R., Cost, W. G., Koopman, R. K. and Zijlstra, W. G., Continuous observation of the percentage oxygen saturation of capillary blood in patients, Arch. Chir. Neerl.1: 184–191, 1949.
3. Cohen, A. and Wadsworth, N. A., Light emitting diode skin reflectance oximeter, Med. Biol. Eng.10: 385–391, 1972.
4. Takatani, S., Cheung, P. W. and Ernst, E. A., A noninvasive tissue reflectance oximeter, Ann. Biomed. Eng. 8: 1–15, 1980.
5. Chaudhary, B. A., and Burk, N. K., Ear oximetry in clinical practice, Amer. Rev. Resp. Dis. 117: 173–175, 1978.