... 2011 VNU Journal of Science, Natural Sciences and Technology 2011 VNU Journal of Science, Mathematics - Physics Vol.27(1S) 2011 VNU Journal of Science, Earth Sciences Vol.26(2), pp.104-118 2011 VNU ... HS 2011 VNU Journal of Science, Natural Sciences and Technology Vol.27, pp.247-255 2011 VNU Journal of Science, Natural Sciences and Technology Vol.27(1S), pp.17-28 2011 VNU Journal of Science, ... Bùi Văn Loát 2011 VNU Journal of Science, Mathematics - Physics Vol.27(1S) 2011 VNU Journal of Science, Natural Sciences and Technology Vol.27(5S), pp.224-233 2011 VNU Journal of Science, Natural...