Cianchi, Andrea
Maz’ya, Vladimir G.
Funding for this research was provided by:
Ministero dell’Istruzione, dell’Università e della Ricerca (2012TC7588)
Istituto Nazionale di Alta Matematica "Francesco Severi
Ministry of Education and Science of the Russian Federation (02.a03.21.0008)
Article History
Received: 14 September 2017
Accepted: 2 February 2018
First Online: 2 May 2018