Opoku, A., K. Iwuji, B. Clough, J. Le, M. Moore, C. Simmons, and B. Hyde. “Discordance Between APTT and Anti-Factor Xa Levels and Implications in Patients Receiving Intravenous Unfractionated Heparin Therapy”. The Southwest Respiratory and Critical Care Chronicles, Vol. 7, no. 30, July 2019, pp. 12-18, doi:10.12746/swrccc.v7i30.559.