1. Department of Pulmonology , Military Hospital, Luanda, Angola
2. CISA – Health Research Centre of Angola, Caxito, Bengo, Angola
3. Centre of Mathematics and Applications, Faculty of Sciences, University of Beira Interior, Covilhã, Portugal
4. Health and Technology Research Centre (H&TRC), Escola Superior de Tecnologia da Saúde de Lisboa, Instituto Politécnico de Lisboa, Portugal