Open Physics
Open Physics > 2009 > 7 > 2 > 237-241
Open Physics > 2011 > 9 > 1 > 242-249
Open Physics > 2011 > 9 > 6 > 1472-1481
Open Physics > 2012 > 10 > 1 > 210-217
Open Physics > 2009 > 7 > 2 > 237-241
Open Physics > 2011 > 9 > 1 > 242-249
Open Physics > 2011 > 9 > 6 > 1472-1481
Open Physics > 2012 > 10 > 1 > 210-217