We are pleased to announce the publication of the following issue: Energies, Volume 6, Issue 4 (April 2013), Pages Pages 1802-2318 http://www.mdpi.com/1996-1073/6/4/ Table of Contents: Diego Iannuzzi, Enrico Pagano and Pietro Tricoli Article: The Use of Energy Storage Systems for Supporting the Voltage Needs of Urban and Suburban Railway Contact Lines Energies 2013, 6(4), 1802-1820; […]