Berger, Pierre
Article History
Received: 24 November 2014
Accepted: 11 October 2015
First Online: 23 November 2015
Change Date: 15 August 2019
Change Type: Correction
Change Date: 15 August 2019
Change Type: Correction
Change Details: All the main results of [2] are correct, but this would need a substantial variation of the proof as done in [3].
Change Details: All the main results of [2] are correct, but this would need a substantial variation of the proof as done in [3].