Custódio, A. L.
Madeira, J. F. A.
Funding for this research was provided by:
Fundação para a Ciência e a Tecnologia (UID/MAT/00297/2013)
Instituto Politécnico de Lisboa
Article History
Received: 15 February 2017
Accepted: 1 February 2018
First Online: 19 February 2018