Md. Sohel Rana, Habshah Midi and A.H.M. Rahmatullah Imon
Journal of Mathematics and Statistics 4 ( 4 ): 277 - 283 , 2008
Md.Sohel Rana, Habshah Midi and A.H.M. Rahmatullah Imon
Journal of Mathematics and Statistics 5 ( 1 ): 54 - 62 , 2009
Arezoo Bagheri, Habshah Midi and A.H.M. Rahmatullah Imon
Journal of Mathematics and Statistics 5 ( 2 ): 97 - 106 , 2009