International Mathematical Forum. Journal for Theory and Applications (Int. Math. Forum) (20110101), 6, no.~45-48, 2201-2215. ISSN: 1312-7594 (print).eISSN: 1314-7536.
International Journal of Pure and Applied Mathematics (Int. J. Pure Appl. Math.) (20110101), 67, no.~4, 363-375. ISSN: 1311-8080 (print).eISSN: 1314-3395.
International Journal of Pure and Applied Mathematics (Int. J. Pure Appl. Math.) (20090101), 50, no.~3, 391-402. ISSN: 1311-8080 (print).eISSN: 1314-3395.
International Journal of Pure and Applied Mathematics International Journal of Pure and Applied Mathematics, Academic Publishing Ltd, 2009, 50 (3), pp.391-402 International Journal of Pure and Applied Mathematics, 2009, 50 (3), pp.391-402