Reliability of the simple 20 minute whole blood clotting test (WBCT20) as an indicator of low plasma fibrinogen concentration in patients envenomed by Bothrops snakes. Butantan Institute Antivenom Study Group. - Sano-Martins, I; Fan, H; Castro, S; Tomy, S; Franca, F; Jorge, M; Kamiguti, A; Warrell, D; Theakston, R (Toxicon : official journal of the International Society on Toxinology, 1994)