Eur. Phys. J. Special Topics 197, 73-74 (2011)
https://doi.org/10.1140/epjst/e2011-01439-6

Regular Article

Discussion Notes

School of Mathematics, University of Birmingham, Birmingham B15 2TT, UK

^a e-mail: yulii@for.mat.bham.ac.uk

Received: 2 June 2011
Revised: 15 June 2011
Published online: 30 August 2011

Abstract

A few comments are made to conclude the discussion initiated by [1].