Luyen, Duong Trong
Ngoan, Ha Tien
Yen, Phung Thi Kim
Funding for this research was provided by:
The International Center for Research and Postgraduate Training in Mathematics—Institute of Mathematics—Vietnam Academy of Science and Technology (ICRTM04-2021.03)
Article History
Received: 13 October 2021
Revised: 26 November 2021
Accepted: 28 November 2021
First Online: 10 January 2022