Villanueva Eleana C, Abreu David Ribeiro de, Cuervo Luis Gabriel, Becerra-Posada Francisco, Reveiz Ludovic, Ijsselmuiden Carel
University of KwaZulu-Natal, Pietermaritzburg, South Africa.
Cad Saude Publica. 2012 Oct;28(10):2003-8. doi: 10.1590/s0102-311x2012001000018.