R. Palani and S. Saravanan
Research Journal of Physics 2 ( 1 ): 13 - 21 , 2008
Research Journal of Physics 4 ( 1 ): 23 - 31 , 2010
R. Palani and A. Geetha
Research Journal of Physics 1 ( 2 ): 82 - 89 , 2007