International Journal of Pure and Applied Mathematics (Int. J. Pure Appl. Math.) (20070101), 38, no.~2, 199-208. ISSN: 1311-8080 (print).eISSN: 1314-3395.
International Journal of Pure and Applied Mathematics (Int. J. Pure Appl. Math.) (20070101), 37, no.~2, 147-160. ISSN: 1311-8080 (print).eISSN: 1314-3395.