Laboratory control of oral anticoagulant treatment by the INR system in patients with the antiphospholipid syndrome and lupus anticoagulant. Results of a collaborative study involving nine commercial thromboplastins - Tripodi,A.; Chantarangkul,V.; Clerici,M.; Negri,B.; Galli,M.; Mannucci,P.M. (Br J Haematol<, 2001)