Rumph B, Bolliger D, Narang N, Molinaro RJ, Levy JH, Szlam F, Tanaka KA. In Vitro Comparative Study of Hemostatic Components in Warfarin-Treated and Fibrinogen-Deficient Plasma. Journal of Cardiothoracic and Vascular Anesthesia. 2010 Jun;24(3):408–12. doi: 10.1053/j.jvca.2009.07.012.