Open Mathematics
Open Mathematics > 2009 > 7 > 4 > 606-616
Open Mathematics > 2013 > 11 > 6 > 1056-1067
Open Mathematics > 2013 > 11 > 6 > 1068-1077
Open Mathematics > 2009 > 7 > 4 > 606-616
Open Mathematics > 2013 > 11 > 6 > 1056-1067
Open Mathematics > 2013 > 11 > 6 > 1068-1077