Primary thrombophilia in Mexico. V. A comprehensive prospective study indicates that most cases are multifactorial - Ruiz-Argüelles, G J; López-Martínez, B; Valdés-Tapia, P; Gómez-Rangel, J D; Reyes-Núñez, V; Garcés-Eisele, J (Am J Hematol, 2005)