Open Physics
Open Physics > 2003 > 1 > 2 > 289-306
Open Physics > 2005 > 3 > 4 > 536-542
Open Physics > 2006 > 4 > 2 > 196-209
Open Physics > 2009 > 7 > 1 > 135-140
Open Physics > 2009 > 7 > 4 > 854-859
Open Physics > 2012 > 10 > 1 > 145-150
Open Physics > 2013 > 11 > 2 > 147-161
Open Physics > 2014 > 12 > 12 > 813-821