@article{articled1804167,
title   = {Racial heterogeneity of dna polymorphisms linked to the a and o alleles of the abo blood group gene},
author = {Zago, M A and Tavella, M H and Simoes, B P and Franco, R F and Guerreiro, J F and Santos, S B},
year = {1996},
journal   = {Annals of Human Genetics}
}