Bermúdez, Teresa http://orcid.org/0000-0002-4034-6060
Zaway, Hajer
Funding for this research was provided by:
Ministerio de Ciencia e Innovación, Spain (MTM2013-47093-P)
University of Gabes (UNG 933989527)
Department of Mathematical Analysis of University of La Laguna
Article History
Received: 19 October 2018
Accepted: 1 April 2019
First Online: 6 May 2019