Open Mathematics
Open Mathematics > 2009 > 7 > 4 > 683-693
Open Mathematics > 2011 > 9 > 6 > 1267-1275
Open Mathematics > 2013 > 11 > 9 > 1677-1688
Open Mathematics > 2014 > 12 > 3 > 476-482
Open Mathematics > 2009 > 7 > 4 > 683-693
Open Mathematics > 2011 > 9 > 6 > 1267-1275
Open Mathematics > 2013 > 11 > 9 > 1677-1688
Open Mathematics > 2014 > 12 > 3 > 476-482