Vietnam Journal of Mathematics
Vietnam Journal of Mathematics > 2013 > 41 > 2 > 149-160
Vietnam Journal of Mathematics > 2013 > 41 > 2 > 121-134
Vietnam Journal of Mathematics > 2013 > 41 > 2 > 233-244
Vietnam Journal of Mathematics > 2013 > 41 > 2 > 167-179
Vietnam Journal of Mathematics > 2013 > 41 > 2 > 217-232
Vietnam Journal of Mathematics > 2013 > 41 > 2 > 161-166
Vietnam Journal of Mathematics > 2013 > 41 > 2 > 135-148
Vietnam Journal of Mathematics > 2013 > 41 > 2 > 181-215