Toan, N. T.
Thuy, L. Q.
Funding for this research was provided by:
National Foundation for Science and Technology Development (the NAFOSTED period 2015-2017)
Vietnam Institute for Advanced Study in Mathematics ((VIASM))
National Foundation for Science and Technology Development (the NAFOSTED period 2015-2017)
Vietnam Institute for Advanced Study in Mathematics ((VIASM))
National Foundation for Science & Technology Development (Vietnam) (the NAFOSTED period 2015-2017)