Published Online: Sep 16, 2019
Page range: 116 - 123
DOI: https://doi.org/10.2478/kjps-2019-0006
© 2019 Tiago Carvalho, published by Sciendo
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.
Tiago Carvalho
Faculdade de Ciências da Universidade de Lisboa,