Zayd Razouki, Burgess, James F. , Ozonoff, Al , Zhao, Shibei , Berlowitz, Dan , and Rose, Adam J. . 2015. “Improving Anticoagulation Measurement”. Circulation: Cardiovascular Quality And Outcomes, 8, 6, Pp. 600–607. doi:10.1161/circoutcomes.115.001789.