Clerbaux, T., Rousseau, M., Nemery, B., Frans, A., & Brasseur, L. (1980). Nitroglycerin and Oxyhemoglobin Dissociation Curve of Human Coronary Sinus Blood. American Heart Journal, 99(3), 404-405. https://doi.org/10.1016/0002-8703(80)90362-2 (Original work published 1980)