Frassu, Silvia
Viglialoro, Giuseppe http://orcid.org/0000-0002-2994-4123
Funding for this research was provided by:
Prin 2017 Nonlinear Differential Problems via Variational, Topological and Set-valued Methods (2017AYM8XW)
Università degli Studi di Cagliari
Article History
Received: 26 June 2020
Accepted: 28 January 2021
First Online: 2 February 2021