The relative power of heat-precipitation nephelometric and clottable (Clauss) fibrinogen in the prediction of ischaemic heart disease: the Caerphilly and Speedwell studies - Sweetnam, PM; Yarnell, JWG; Lowe, GDO; Baker, IA; O’Brien, JR; Rumley, A; Etherington, MD; Whitehead, PJ; Elwood, PC (Br J Haematol, 1998)