Applied Mathematics Letters
Applied Mathematics Letters > 2013 > 26 > 7 > 699-705
Applied Mathematics Letters > 2013 > 26 > 7 > 766-768
Applied Mathematics Letters > 2013 > 26 > 7 > 729-734
Applied Mathematics Letters > 2013 > 26 > 7 > 769-773
Applied Mathematics Letters > 2013 > 26 > 7 > 787-793
Applied Mathematics Letters > 2013 > 26 > 7 > 794-798