Norma Cristina Sousa, Joyce Maria Anicchino-Bizzacchi, Maria Fátima Locatelli, Vagner Castro and Maria Lourdes Barjas-Castro (2007) “The relationship between ABO groups and subgroups, factor VIII and von Willebrand factor”, Haematologica. Pavia, Italy, 92(2), pp. 236-239. doi: 10.3324/haematol.10457.