Immunologic differentiation of classic hemophilia (Factor VIII deficiency) and von Wille-brand’s disease. With observations on combined deficiencies of antihemophilic factor and proaccelerin (Factor V) and on an acquired circulating anticoagulant against antihemophilic factor - Zimmerman, TS; Ratnoff, OD; Powell, AE (J Clin Invest, 1971)